diff --git a/artifacts/api-server/package.json b/artifacts/api-server/package.json
index 45518dc..59b62df 100644
--- a/artifacts/api-server/package.json
+++ b/artifacts/api-server/package.json
@@ -7,7 +7,8 @@
     "dev": "export NODE_ENV=development && pnpm run build && pnpm run start",
     "build": "node ./build.mjs",
     "start": "node --enable-source-maps ./dist/index.mjs",
-    "typecheck": "tsc -p tsconfig.json --noEmit"
+    "typecheck": "tsc -p tsconfig.json --noEmit",
+    "test": "vitest run"
   },
   "dependencies": {
     "@workspace/api-zod": "workspace:*",
@@ -28,6 +29,7 @@
     "esbuild": "0.27.3",
     "esbuild-plugin-pino": "^2.3.3",
     "pino-pretty": "^13.1.3",
-    "thread-stream": "3.1.0"
+    "thread-stream": "3.1.0",
+    "vitest": "^4.1.8"
   }
 }
diff --git a/artifacts/api-server/src/lib/lineDiff.test.ts b/artifacts/api-server/src/lib/lineDiff.test.ts
new file mode 100644
index 0000000..f50d89a
--- /dev/null
+++ b/artifacts/api-server/src/lib/lineDiff.test.ts
@@ -0,0 +1,95 @@
+import { describe, it, expect } from "vitest";
+import { lineSimilarity, lineDiff } from "./lineDiff";
+
+describe("lineSimilarity", () => {
+  it("is 1 for identical text", () => {
+    const text = "line one\nline two\nline three";
+    expect(lineSimilarity(text, text)).toBe(1);
+  });
+
+  it("is 1 for two empty strings", () => {
+    expect(lineSimilarity("", "")).toBe(1);
+  });
+
+  it("is high for a single changed line", () => {
+    const prev = "a\nb\nc\nd";
+    const curr = "a\nB\nc\nd"; // one of four lines changed
+    const sim = lineSimilarity(prev, curr);
+    // LCS = {a,c,d} = 3, ratio = 2*3 / (4+4) = 0.75
+    expect(sim).toBeCloseTo(0.75, 10);
+    expect(sim).toBeGreaterThan(0.5);
+  });
+
+  it("is 0 when nothing is in common", () => {
+    expect(lineSimilarity("a\nb\nc", "x\ny\nz")).toBe(0);
+  });
+
+  it("is symmetric", () => {
+    const a = "one\ntwo\nthree\nfour";
+    const b = "one\ntwo\nTHREE\nfour\nfive";
+    expect(lineSimilarity(a, b)).toBeCloseTo(lineSimilarity(b, a), 10);
+  });
+
+  it("handles \\r\\n and \\n line endings equivalently", () => {
+    expect(lineSimilarity("a\r\nb", "a\nb")).toBe(1);
+  });
+});
+
+describe("lineDiff", () => {
+  it("marks every line as context for identical input", () => {
+    const text = "a\nb\nc";
+    const diff = lineDiff(text, text);
+    expect(diff).not.toBeNull();
+    expect(diff!.every((d) => d.type === "context")).toBe(true);
+    expect(diff!.map((d) => d.text)).toEqual(["a", "b", "c"]);
+  });
+
+  it("records a removed and an added line for a single-line edit", () => {
+    const diff = lineDiff("a\nb\nc", "a\nB\nc");
+    expect(diff).not.toBeNull();
+    const removed = diff!.filter((d) => d.type === "remove");
+    const added = diff!.filter((d) => d.type === "add");
+    expect(removed.map((d) => d.text)).toEqual(["b"]);
+    expect(added.map((d) => d.text)).toEqual(["B"]);
+    // unchanged lines remain context
+    expect(diff!.filter((d) => d.type === "context").map((d) => d.text)).toEqual(
+      ["a", "c"],
+    );
+  });
+
+  it("sets correct line numbers for context, add and remove", () => {
+    const diff = lineDiff("a\nb", "a\nb\nc")!;
+    const added = diff.find((d) => d.type === "add")!;
+    expect(added.text).toBe("c");
+    expect(added.previousLine).toBeNull();
+    expect(added.currentLine).toBe(3);
+
+    const firstContext = diff.find((d) => d.type === "context")!;
+    expect(firstContext.previousLine).toBe(1);
+    expect(firstContext.currentLine).toBe(1);
+  });
+
+  it("treats a pure addition as only added lines", () => {
+    const diff = lineDiff("a", "a\nb\nc")!;
+    expect(diff.filter((d) => d.type === "remove")).toHaveLength(0);
+    expect(diff.filter((d) => d.type === "add").map((d) => d.text)).toEqual([
+      "b",
+      "c",
+    ]);
+  });
+
+  it("treats a pure removal as only removed lines", () => {
+    const diff = lineDiff("a\nb\nc", "a")!;
+    expect(diff.filter((d) => d.type === "add")).toHaveLength(0);
+    expect(diff.filter((d) => d.type === "remove").map((d) => d.text)).toEqual([
+      "b",
+      "c",
+    ]);
+  });
+
+  it("returns null when either side exceeds the diff line cap", () => {
+    const big = Array.from({ length: 2001 }, (_, i) => `line ${i}`).join("\n");
+    expect(lineDiff(big, "a")).toBeNull();
+    expect(lineDiff("a", big)).toBeNull();
+  });
+});
diff --git a/artifacts/api-server/src/lib/skillFingerprint.test.ts b/artifacts/api-server/src/lib/skillFingerprint.test.ts
new file mode 100644
index 0000000..a751e4e
--- /dev/null
+++ b/artifacts/api-server/src/lib/skillFingerprint.test.ts
@@ -0,0 +1,98 @@
+import { describe, it, expect } from "vitest";
+import {
+  hashText,
+  hashBytes,
+  computeFingerprint,
+  jaccard,
+} from "./skillFingerprint";
+
+describe("hashText / hashBytes", () => {
+  it("produces a stable sha256 hex digest", () => {
+    const h = hashText("hello world");
+    expect(h).toBe(
+      "b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9",
+    );
+    expect(h).toMatch(/^[0-9a-f]{64}$/);
+  });
+
+  it("agrees between hashText and hashBytes for the same content", () => {
+    const text = "some skill content\nwith two lines";
+    expect(hashText(text)).toBe(hashBytes(Buffer.from(text, "utf-8")));
+  });
+
+  it("changes when the content changes", () => {
+    expect(hashText("a")).not.toBe(hashText("b"));
+  });
+});
+
+describe("computeFingerprint", () => {
+  const files = [
+    { path: "SKILL.md", hash: "aaa" },
+    { path: "scripts/run.sh", hash: "bbb" },
+    { path: "data.json", hash: "ccc" },
+  ];
+
+  it("is stable across calls with the same input", () => {
+    expect(computeFingerprint(files)).toBe(computeFingerprint(files));
+  });
+
+  it("is independent of the order files are supplied in", () => {
+    const reordered = [files[2], files[0], files[1]];
+    expect(computeFingerprint(reordered)).toBe(computeFingerprint(files));
+  });
+
+  it("changes when a file's content hash changes", () => {
+    const changed = [
+      files[0],
+      { path: "scripts/run.sh", hash: "DIFFERENT" },
+      files[2],
+    ];
+    expect(computeFingerprint(changed)).not.toBe(computeFingerprint(files));
+  });
+
+  it("changes when a file's path changes", () => {
+    const renamed = [
+      { path: "SKILL.md", hash: "aaa" },
+      { path: "scripts/start.sh", hash: "bbb" },
+      files[2],
+    ];
+    expect(computeFingerprint(renamed)).not.toBe(computeFingerprint(files));
+  });
+
+  it("changes when a file is added or removed", () => {
+    const fewer = [files[0], files[1]];
+    expect(computeFingerprint(fewer)).not.toBe(computeFingerprint(files));
+  });
+
+  it("returns a 64-char hex digest", () => {
+    expect(computeFingerprint(files)).toMatch(/^[0-9a-f]{64}$/);
+  });
+});
+
+describe("jaccard", () => {
+  it("is 1 for identical non-empty sets", () => {
+    expect(jaccard(new Set(["a", "b"]), new Set(["a", "b"]))).toBe(1);
+  });
+
+  it("is 0 for disjoint sets", () => {
+    expect(jaccard(new Set(["a"]), new Set(["b"]))).toBe(0);
+  });
+
+  it("computes intersection over union for partial overlap", () => {
+    // intersection {a} = 1, union {a,b,c} = 3
+    expect(jaccard(new Set(["a", "b"]), new Set(["a", "c"]))).toBeCloseTo(
+      1 / 3,
+      10,
+    );
+  });
+
+  it("is symmetric", () => {
+    const a = new Set(["a", "b", "c"]);
+    const b = new Set(["b", "c", "d"]);
+    expect(jaccard(a, b)).toBe(jaccard(b, a));
+  });
+
+  it("treats two empty sets as 0 (no overlap to report)", () => {
+    expect(jaccard(new Set(), new Set())).toBe(0);
+  });
+});
diff --git a/artifacts/api-server/src/routes/compare.test.ts b/artifacts/api-server/src/routes/compare.test.ts
new file mode 100644
index 0000000..55eebd8
--- /dev/null
+++ b/artifacts/api-server/src/routes/compare.test.ts
@@ -0,0 +1,151 @@
+import { describe, it, expect, beforeAll, afterAll } from "vitest";
+import type { AddressInfo } from "node:net";
+import type { Server } from "node:http";
+import app from "../app";
+import { db, pool, scansTable, scanFilesTable } from "@workspace/db";
+import { inArray } from "drizzle-orm";
+import { hashText, computeFingerprint } from "../lib/skillFingerprint";
+
+const emptyCounts = {
+  critical: 0,
+  high: 0,
+  medium: 0,
+  low: 0,
+  info: 0,
+  security: 0,
+  privacy: 0,
+  total: 0,
+};
+
+type FixtureFile = { path: string; content: string };
+
+const createdScanIds: number[] = [];
+let server: Server;
+let baseUrl: string;
+
+beforeAll(async () => {
+  await new Promise<void>((resolve) => {
+    server = app.listen(0, () => resolve());
+  });
+  const { port } = server.address() as AddressInfo;
+  baseUrl = `http://127.0.0.1:${port}`;
+});
+
+afterAll(async () => {
+  if (createdScanIds.length > 0) {
+    await db
+      .delete(scansTable)
+      .where(inArray(scansTable.id, createdScanIds.splice(0)));
+  }
+  await new Promise<void>((resolve, reject) => {
+    server.close((err) => (err ? reject(err) : resolve()));
+  });
+  await pool.end();
+});
+
+async function insertScan(
+  name: string,
+  files: FixtureFile[],
+): Promise<number> {
+  const withHash = files.map((f) => ({ ...f, hash: hashText(f.content) }));
+  const fingerprint = computeFingerprint(
+    withHash.map((f) => ({ path: f.path, hash: f.hash })),
+  );
+  const [scan] = await db
+    .insert(scansTable)
+    .values({
+      name,
+      source: "zip",
+      status: "completed",
+      verdict: "pass",
+      riskScore: 0,
+      fileCount: files.length,
+      aiUsed: false,
+      findingCounts: emptyCounts,
+      fingerprint,
+      relation: "new",
+    })
+    .returning();
+  createdScanIds.push(scan.id);
+  await db.insert(scanFilesTable).values(
+    withHash.map((f) => ({
+      scanId: scan.id,
+      path: f.path,
+      kind: f.path.toLowerCase().endsWith(".md") ? "instruction" : "resource",
+      language: null,
+      size: Buffer.byteLength(f.content, "utf-8"),
+      hash: f.hash,
+      content: f.content,
+    })),
+  );
+  return scan.id;
+}
+
+describe("GET /api/scans/:id/compare/:otherId", () => {
+  it("returns correct per-file statuses and a line diff for the modified file", async () => {
+    const previousId = await insertScan("v1", [
+      { path: "SKILL.md", content: "# Skill\nstep one\nstep two\nstep three" },
+      { path: "removed.md", content: "this file goes away" },
+      { path: "stable.md", content: "never changes" },
+    ]);
+    const currentId = await insertScan("v2", [
+      {
+        path: "SKILL.md",
+        content: "# Skill\nstep one\nstep TWO\nstep three",
+      },
+      { path: "added.md", content: "brand new file" },
+      { path: "stable.md", content: "never changes" },
+    ]);
+
+    const res = await fetch(
+      `${baseUrl}/api/scans/${currentId}/compare/${previousId}`,
+    );
+    expect(res.status).toBe(200);
+    const body = (await res.json()) as {
+      current: { id: number };
+      previous: { id: number };
+      files: {
+        path: string;
+        status: string;
+        lineDiff: { type: string; text: string }[] | null;
+      }[];
+    };
+
+    expect(body.current.id).toBe(currentId);
+    expect(body.previous.id).toBe(previousId);
+
+    const byPath: Record<string, (typeof body.files)[number]> =
+      Object.fromEntries(body.files.map((f) => [f.path, f]));
+
+    expect(byPath["SKILL.md"].status).toBe("modified");
+    expect(byPath["stable.md"].status).toBe("unchanged");
+    expect(byPath["added.md"].status).toBe("added");
+    expect(byPath["removed.md"].status).toBe("removed");
+
+    // Files are returned sorted by path.
+    expect(body.files.map((f: { path: string }) => f.path)).toEqual(
+      ["SKILL.md", "added.md", "removed.md", "stable.md"],
+    );
+
+    // The modified text file carries a line diff with the changed line.
+    const diff = byPath["SKILL.md"].lineDiff as
+      | { type: string; text: string }[]
+      | null;
+    expect(diff).not.toBeNull();
+    expect(diff!.find((d) => d.type === "remove")?.text).toBe("step two");
+    expect(diff!.find((d) => d.type === "add")?.text).toBe("step TWO");
+    expect(diff!.filter((d) => d.type === "context").map((d) => d.text)).toEqual(
+      ["# Skill", "step one", "step three"],
+    );
+
+    // Unchanged / added / removed files do not get a line diff.
+    expect(byPath["stable.md"].lineDiff).toBeNull();
+    expect(byPath["added.md"].lineDiff).toBeNull();
+    expect(byPath["removed.md"].lineDiff).toBeNull();
+  });
+
+  it("returns 404 when a scan does not exist", async () => {
+    const res = await fetch(`${baseUrl}/api/scans/999999999/compare/999999998`);
+    expect(res.status).toBe(404);
+  });
+});
diff --git a/artifacts/api-server/src/routes/relation.test.ts b/artifacts/api-server/src/routes/relation.test.ts
new file mode 100644
index 0000000..5133977
--- /dev/null
+++ b/artifacts/api-server/src/routes/relation.test.ts
@@ -0,0 +1,195 @@
+import { describe, it, expect, afterEach, afterAll } from "vitest";
+import { db, pool, scansTable, scanFilesTable } from "@workspace/db";
+import { eq, inArray } from "drizzle-orm";
+import { hashText, computeFingerprint } from "../lib/skillFingerprint";
+import type { ParsedFile } from "../lib/ruleCatalog";
+import {
+  computeRelation,
+  computeContentSimilarity,
+  countFingerprint,
+} from "./scans";
+
+const emptyCounts = {
+  critical: 0,
+  high: 0,
+  medium: 0,
+  low: 0,
+  info: 0,
+  security: 0,
+  privacy: 0,
+  total: 0,
+};
+
+const createdScanIds: number[] = [];
+
+function file(path: string, content: string): ParsedFile {
+  return {
+    path,
+    kind: path.toLowerCase().endsWith(".md") ? "instruction" : "resource",
+    language: null,
+    content,
+    size: Buffer.byteLength(content, "utf-8"),
+    hash: hashText(content),
+    isBinary: false,
+  };
+}
+
+async function insertScan(name: string, files: ParsedFile[]): Promise<number> {
+  const fingerprint = computeFingerprint(
+    files.map((f) => ({ path: f.path, hash: f.hash })),
+  );
+  const [scan] = await db
+    .insert(scansTable)
+    .values({
+      name,
+      source: "text",
+      status: "completed",
+      verdict: "pass",
+      riskScore: 0,
+      fileCount: files.length,
+      aiUsed: false,
+      findingCounts: emptyCounts,
+      fingerprint,
+      relation: "new",
+    })
+    .returning();
+  createdScanIds.push(scan.id);
+  await db.insert(scanFilesTable).values(
+    files.map((f) => ({
+      scanId: scan.id,
+      path: f.path,
+      kind: f.kind,
+      language: f.language,
+      size: f.size,
+      hash: f.hash,
+      content: f.isBinary ? null : f.content,
+    })),
+  );
+  return scan.id;
+}
+
+afterEach(async () => {
+  if (createdScanIds.length > 0) {
+    await db
+      .delete(scansTable)
+      .where(inArray(scansTable.id, createdScanIds.splice(0)));
+  }
+});
+
+afterAll(async () => {
+  await pool.end();
+});
+
+describe("computeRelation", () => {
+  it("flags byte-identical content (with a different name) as identical and bumps the check counter", async () => {
+    // Use highly unique content so the fingerprint cannot collide with any
+    // pre-existing scans in the shared dev database.
+    const body =
+      "# Unique relation-test skill " +
+      Math.random().toString(36).slice(2) +
+      "\nDo a very specific thing.\n";
+    const original = [file("SKILL.md", body)];
+    const baselineId = await insertScan("Original Name", original);
+
+    const fingerprint = computeFingerprint(
+      original.map((f) => ({ path: f.path, hash: f.hash })),
+    );
+
+    // A re-upload of the exact same bytes under a different display name.
+    const relation = await computeRelation(fingerprint, original);
+    expect(relation.relation).toBe("identical");
+    expect(relation.similarity).toBe(100);
+    expect(relation.comparedScanId).toBe(baselineId);
+
+    // Check counter: only the baseline exists so far -> 1.
+    expect(await countFingerprint(fingerprint)).toBe(1);
+    // Storing the identical re-upload increments the counter to 2.
+    await insertScan("Different Name", original);
+    expect(await countFingerprint(fingerprint)).toBe(2);
+  });
+
+  it("flags a one-line edit to a single-file skill as modified with a sensible similarity", async () => {
+    const tag = Math.random().toString(36).slice(2);
+    const baseLines = [
+      `# Modified-test skill ${tag}`,
+      "Step one: gather inputs.",
+      "Step two: process them.",
+      "Step three: report results.",
+      "Step four: clean up.",
+    ];
+    const original = [file("SKILL.md", baseLines.join("\n"))];
+    const baselineId = await insertScan("Edited Skill", original);
+
+    // Change exactly one line.
+    const editedLines = [...baseLines];
+    editedLines[2] = "Step two: process them carefully.";
+    const edited = [file("SKILL.md", editedLines.join("\n"))];
+    const fingerprint = computeFingerprint(
+      edited.map((f) => ({ path: f.path, hash: f.hash })),
+    );
+
+    const relation = await computeRelation(fingerprint, edited);
+    expect(relation.relation).toBe("modified");
+    expect(relation.comparedScanId).toBe(baselineId);
+    expect(relation.similarity).not.toBeNull();
+    // One of five lines changed -> high but not perfect similarity.
+    expect(relation.similarity!).toBeGreaterThanOrEqual(60);
+    expect(relation.similarity!).toBeLessThan(100);
+  });
+
+  it("flags an unrelated single-file skill as new", async () => {
+    const tag = Math.random().toString(36).slice(2);
+    // Establish a baseline skill.
+    await insertScan("Baseline Skill", [
+      file(
+        "SKILL.md",
+        `# Baseline ${tag}\nalpha bravo charlie\ndelta echo foxtrot\ngolf hotel india`,
+      ),
+    ]);
+
+    // A completely different single-file skill. It shares the common path
+    // "SKILL.md" but has no content overlap, so it must be "new".
+    const unrelated = [
+      file(
+        "SKILL.md",
+        `# Totally different ${tag}\nzulu yankee xray\nwhiskey victor uniform\ntango sierra romeo`,
+      ),
+    ];
+    const fingerprint = computeFingerprint(
+      unrelated.map((f) => ({ path: f.path, hash: f.hash })),
+    );
+
+    const relation = await computeRelation(fingerprint, unrelated);
+    expect(relation.relation).toBe("new");
+    expect(relation.similarity).toBeNull();
+    expect(relation.comparedScanId).toBeNull();
+  });
+});
+
+describe("computeContentSimilarity", () => {
+  it("is 100 when every file is byte-identical", () => {
+    const files = [file("SKILL.md", "same content\nline two")];
+    const prior = new Map(
+      files.map((f) => [f.path, { hash: f.hash, content: f.content }]),
+    );
+    expect(computeContentSimilarity(files, prior)).toBe(100);
+  });
+
+  it("uses line-level similarity for a changed text file", () => {
+    const current = [file("SKILL.md", "a\nB\nc\nd")];
+    const prior = new Map([
+      ["SKILL.md", { hash: hashText("a\nb\nc\nd"), content: "a\nb\nc\nd" }],
+    ]);
+    // 3 of 4 lines shared -> 0.75 -> 75 (single shared path).
+    expect(computeContentSimilarity(current, prior)).toBe(75);
+  });
+
+  it("counts added or removed files as zero contribution", () => {
+    const current = [file("SKILL.md", "shared"), file("extra.md", "new file")];
+    const prior = new Map([
+      ["SKILL.md", { hash: hashText("shared"), content: "shared" }],
+    ]);
+    // SKILL.md identical (1.0), extra.md added (0). Union of paths = 2 -> 50.
+    expect(computeContentSimilarity(current, prior)).toBe(50);
+  });
+});
diff --git a/artifacts/api-server/src/routes/scans.ts b/artifacts/api-server/src/routes/scans.ts
index ddff4de..29e1748 100644
--- a/artifacts/api-server/src/routes/scans.ts
+++ b/artifacts/api-server/src/routes/scans.ts
@@ -90,7 +90,7 @@ async function resolveComparedScan(
   };
 }
 
-async function countFingerprint(fingerprint: string): Promise<number> {
+export async function countFingerprint(fingerprint: string): Promise<number> {
   if (!fingerprint) return 1;
   const [row] = await db
     .select({ c: count() })
@@ -156,7 +156,7 @@ type RelationInfo = {
  * skill (when it overlaps enough or shares a byte-identical file) -> modified;
  * nothing meaningfully in common -> new.
  */
-async function computeRelation(
+export async function computeRelation(
   fingerprint: string,
   files: ParsedFile[],
 ): Promise<RelationInfo> {
@@ -261,7 +261,7 @@ const MODIFIED_SIMILARITY_THRESHOLD = 40;
  * scan. Identical files (same hash) count fully; changed text files use the
  * line-level similarity; added/removed or changed binary files count as 0.
  */
-function computeContentSimilarity(
+export function computeContentSimilarity(
   newFiles: ParsedFile[],
   prior: Map<string, { hash: string; content: string | null }>,
 ): number {
diff --git a/artifacts/api-server/vitest.config.ts b/artifacts/api-server/vitest.config.ts
new file mode 100644
index 0000000..54ca4ec
--- /dev/null
+++ b/artifacts/api-server/vitest.config.ts
@@ -0,0 +1,11 @@
+import { defineConfig } from "vitest/config";
+
+export default defineConfig({
+  resolve: {
+    conditions: ["workspace"],
+  },
+  test: {
+    include: ["src/**/*.test.ts"],
+    environment: "node",
+  },
+});
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 888f97f..e7a696c 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -218,6 +218,9 @@ importers:
       thread-stream:
         specifier: 3.1.0
         version: 3.1.0
+      vitest:
+        specifier: ^4.1.8
+        version: 4.1.8(@types/node@25.6.2)(jiti@2.7.0)(lightningcss@1.32.0)(tsx@4.21.0)(yaml@2.8.4)
 
   artifacts/mockup-sandbox:
     devDependencies:
@@ -1568,6 +1571,9 @@ packages:
     resolution: {integrity: sha512-tlqY9xq5ukxTUZBmoOp+m61cqwQD5pHJtFY3Mn8CA8ps6yghLH/Hw8UPdqg4OLmFW3IFlcXnQNmo/dh8HzXYIQ==}
     engines: {node: '>=18'}
 
+  '@standard-schema/spec@1.1.0':
+    resolution: {integrity: sha512-l2aFy5jALhniG5HgqrD6jXLi/rUWrKvqN/qJx6yoJsgKhblVd+iqqU4RCXavm/jPityDo5TCvKMnpjKnOriy0w==}
+
   '@tabby_ai/hijri-converter@1.0.5':
     resolution: {integrity: sha512-r5bClKrcIusDoo049dSL8CawnHR6mRdDwhlQuIgZRNty68q0x8k3Lf1BtPAMxRf/GgnHBnIO4ujd3+GQdLWzxQ==}
     engines: {node: '>=16.0.0'}
@@ -1631,6 +1637,9 @@ packages:
   '@types/body-parser@1.19.6':
     resolution: {integrity: sha512-HLFeCYgz89uk22N5Qg3dvGvsv46B8GLvKKo1zKG4NybA8U2DiEO3w9lqGg29t/tfLRJpJ6iQxnVw4OnB7MoM9g==}
 
+  '@types/chai@5.2.3':
+    resolution: {integrity: sha512-Mw558oeA9fFbv65/y4mHtXDs9bPnFMZAL/jxdPFUpOHHIXX91mcgEHbS5Lahr+pwZFR8A7GQleRWeI6cGFC2UA==}
+
   '@types/connect@3.4.38':
     resolution: {integrity: sha512-K6uROf1LD88uDQqJCktA4yzL1YYAK6NgfsI0v/mTgyPKWsX1CnJ0XPSDhViejru1GcRkLWb8RlzFYJRqGUbaug==}
 
@@ -1669,6 +1678,9 @@ packages:
   '@types/d3-timer@3.0.2':
     resolution: {integrity: sha512-Ps3T8E8dZDam6fUyNiMkekK3XUsaUEik+idO9/YjPtfj2qruF8tFBXS7XhtE4iIXBLxhmLjP3SXpLhVf21I9Lw==}
 
+  '@types/deep-eql@4.0.2':
+    resolution: {integrity: sha512-c9h9dVVMigMPc4bwTvC5dxqtqJZwQPePsWjPlpSOnojbor6pGqdk541lfA7AqFQr5pB1BRdq0juY9db81BwyFw==}
+
   '@types/estree@1.0.8':
     resolution: {integrity: sha512-dWHzHa2WqEXI/O1E9OjrocMTKJl2mSrEolh1Iomrv6U+JuNwaHXsXx9bLu5gG7BUWFIN0skIQJQ/L1rIex4X6w==}
 
@@ -1719,6 +1731,35 @@ packages:
     peerDependencies:
       vite: ^4.2.0 || ^5.0.0 || ^6.0.0 || ^7.0.0 || ^8.0.0
 
+  '@vitest/expect@4.1.8':
+    resolution: {integrity: sha512-h3nDO677RDLEGlBxyQ5CW8RlMThSKSRLUePLOx09gNIWRL40edgA1GCZSZgf1W55MFAG6/Sw14KeaAnqv0NKdQ==}
+
+  '@vitest/mocker@4.1.8':
+    resolution: {integrity: sha512-LEiN/xe4OSIbKe9HQIp5OC24agGD9J5CnmMgsLohVVoOPWL9a2sBoR6VBx43jQZb7Kr1l4RCuyCJzcAa0+dojw==}
+    peerDependencies:
+      msw: ^2.4.9
+      vite: ^6.0.0 || ^7.0.0 || ^8.0.0
+    peerDependenciesMeta:
+      msw:
+        optional: true
+      vite:
+        optional: true
+
+  '@vitest/pretty-format@4.1.8':
+    resolution: {integrity: sha512-9GasEBxpZ1VYIpqHf/0+YGg121uSNwCKOJqIrTwWP/TB7DmFCiaBpNl3aPZzoLWfWkuqhbH8vJIVobZkvdo2cA==}
+
+  '@vitest/runner@4.1.8':
+    resolution: {integrity: sha512-EmVxeBAfMJvycdjd6Hm+RbFBbA9fKvo0Kx37hNpBYoYeavH3RNsBXWDooR1mgD52dCrxIIuP7UotpfiwOikvcg==}
+
+  '@vitest/snapshot@4.1.8':
+    resolution: {integrity: sha512-acfZboRmAIf05DEKcBQy33VXojFJjtUdLyo7oOmV9kebb2xdU01UknNiPuPZoJZQyO7DF0gZdTGTpeAzET9QPQ==}
+
+  '@vitest/spy@4.1.8':
+    resolution: {integrity: sha512-6EevtBp6OZOPF7bmz36HrGMeP3txgVSrgebWxHOafDXGkhIzfXK14f8KF6MuFfgXXUeHxmpD3BQxkV00/3s5mA==}
+
+  '@vitest/utils@4.1.8':
+    resolution: {integrity: sha512-uOJamYALNhfJ6iolExyQM40yIQwDqYnkKtQ5VCiSe17E33H0aQ/u+1GlRuz4LZBk6Mm3sg90G9hEbmEt37C1Zg==}
+
   accepts@2.0.0:
     resolution: {integrity: sha512-5cvg6CtKwfgdmVqY1WIiXKc3Q1bkRqGLi+2W/6ao+6Y7gu/RCwRuAhGEzh5B4KlszSuTLgZYuqFqo5bImjNKng==}
     engines: {node: '>= 0.6'}
@@ -1757,6 +1798,10 @@ packages:
     resolution: {integrity: sha512-ik3ZgC9dY/lYVVM++OISsaYDeg1tb0VtP5uL3ouh1koGOaUMDPpbFIei4JkFimWUFPn90sbMNMXQAIVOlnYKJA==}
     engines: {node: '>=10'}
 
+  assertion-error@2.0.1:
+    resolution: {integrity: sha512-Izi8RQcffqCeNVgFigKli1ssklIbpHnCYc6AknXGYoB6grJqyeby7jv12JUQgmTAnIDnbck1uxksT4dzN3PWBA==}
+    engines: {node: '>=12'}
+
   atomic-sleep@1.0.0:
     resolution: {integrity: sha512-kNOjDqAh7px0XWNI+4QbzoiR/nTkHAWNud2uvnJquD1/x5a7EQZMJT0AczqK0Qn67oY/TTQ1LbUKajZpp3I9tQ==}
     engines: {node: '>=8.0.0'}
@@ -1802,6 +1847,10 @@ packages:
   caniuse-lite@1.0.30001792:
     resolution: {integrity: sha512-hVLMUZFgR4JJ6ACt1uEESvQN1/dBVqPAKY0hgrV70eN3391K6juAfTjKZLKvOMsx8PxA7gsY1/tLMMTcfFLLpw==}
 
+  chai@6.2.2:
+    resolution: {integrity: sha512-NUPRluOfOiTKBKvWPtSD4PhFvWCqOi0BGStNWs57X9js7XGTprSmFoz5F0tWhR4WPjNeR9jXqdC7/UpSJTnlRg==}
+    engines: {node: '>=18'}
+
   chokidar@4.0.3:
     resolution: {integrity: sha512-Qgzu8kfBvo+cA4962jnP1KkS6Dop5NS6g7R5LFYJr4b8Ub94PPQXUksCw9PvXoeXPRRddRNC5C1JQUR2SMGtnA==}
     engines: {node: '>= 14.16.0'}
@@ -2109,6 +2158,9 @@ packages:
     resolution: {integrity: sha512-Zf5H2Kxt2xjTvbJvP2ZWLEICxA6j+hAmMzIlypy4xcBg1vKVnx89Wy0GbS+kf5cwCVFFzdCFh2XSCFNULS6csw==}
     engines: {node: '>= 0.4'}
 
+  es-module-lexer@2.1.0:
+    resolution: {integrity: sha512-n27zTYMjYu1aj4MjCWzSP7G9r75utsaoc8m61weK+W8JMBGGQybd43GstCXZ3WNmSFtGT9wi59qQTW6mhTR5LQ==}
+
   es-object-atoms@1.1.1:
     resolution: {integrity: sha512-FGgH2h8zKNim9ljj7dankFPcICIK9Cp5bm+c2gQSYePhpaG5+esrLODihIorn+Pe6FGJzWhXQotPv73jTaldXA==}
     engines: {node: '>= 0.4'}
@@ -2138,6 +2190,9 @@ packages:
   escape-html@1.0.3:
     resolution: {integrity: sha512-NiSupZ4OeuGwr68lGIeym/ksIZMJodUGOSCZ/FSnTxcrekbvqrgdUxlJOMpijaKZVjAJrWrGs/6Jy8OMuyj9ow==}
 
+  estree-walker@3.0.3:
+    resolution: {integrity: sha512-7RUKfXgSMMkzt6ZuXmqapOurLGPPfgj6l9uRZ7lRGolvk0y2yocc35LdcxKC5PQZdn2DMqioAQ2NoWcrTKmm6g==}
+
   esutils@2.0.3:
     resolution: {integrity: sha512-kVscqXk4OCp68SZ0dkgEKVi6/8ij300KBWTJq32P/dYeWTSwK41WyTxalN1eRmA5Z9UU/LX9D7FWSmV9SAYx6g==}
     engines: {node: '>=0.10.0'}
@@ -2153,6 +2208,10 @@ packages:
     resolution: {integrity: sha512-9Be3ZoN4LmYR90tUoVu2te2BsbzHfhJyfEiAVfz7N5/zv+jduIfLrV2xdQXOHbaD6KgpGdO9PRPM1Y4Q9QkPkA==}
     engines: {node: ^18.19.0 || >=20.5.0}
 
+  expect-type@1.3.0:
+    resolution: {integrity: sha512-knvyeauYhqjOYvQ66MznSMs83wmHrCycNEN6Ao+2AeYEfxUIkuiVxdEa1qlGEPK+We3n0THiDciYSsCcgW/DoA==}
+    engines: {node: '>=12.0.0'}
+
   express@5.2.1:
     resolution: {integrity: sha512-hIS4idWWai69NezIdRt2xFVofaF4j+6INOpJlVOLDO8zXGpUVEVzIYk12UUi2JzjEzWL3IOAxcTubgz9Po0yXw==}
     engines: {node: '>= 18'}
@@ -2527,6 +2586,10 @@ packages:
     resolution: {integrity: sha512-W67iLl4J2EXEGTbfeHCffrjDfitvLANg0UlX3wFUUSTx92KXRFegMHUVgSqE+wvhAbi4WqjGg9czysTV2Epbew==}
     engines: {node: '>= 0.4'}
 
+  obug@2.1.2:
+    resolution: {integrity: sha512-AWGB9WFcRXOQs48Z/udjI5ZcZMHXwX8XPByNpOydgcGsDLIzjGizhoMWJyKAWze7AVW/2W1i+/gPX4YtKe5cyg==}
+    engines: {node: '>=12.20.0'}
+
   on-exit-leak-free@2.1.2:
     resolution: {integrity: sha512-0eJJY6hXLGf1udHwfNftBqH+g73EU4B504nZeKpz1sYRKafAghwxEJunB2O7rDZkL4PGfsMVnTXZ2EjibbqcsA==}
     engines: {node: '>=14.0.0'}
@@ -2900,6 +2963,9 @@ packages:
     resolution: {integrity: sha512-ZX99e6tRweoUXqR+VBrslhda51Nh5MTQwou5tnUDgbtyM0dBgmhEDtWGP/xbKn6hqfPRHujUNwz5fy/wbbhnpw==}
     engines: {node: '>= 0.4'}
 
+  siginfo@2.0.0:
+    resolution: {integrity: sha512-ybx0WO1/8bSBLEWXZvEd7gMW3Sn3JFlW3TvX1nREbDLRNQNaeNN8WK0meBwPdAaOI7TtRRRJn/Es1zhrrCHu7g==}
+
   signal-exit@4.1.0:
     resolution: {integrity: sha512-bzyZ1e88w9O1iNJbKnOlvYTrWPDl46O1bG0D3XInv+9tkPrxrN8jUUTiFlDkkmKWgn1M6CfIA13SuGqOa9Korw==}
     engines: {node: '>=14'}
@@ -2925,10 +2991,16 @@ packages:
     resolution: {integrity: sha512-UcjcJOWknrNkF6PLX83qcHM6KHgVKNkV62Y8a5uYDVv9ydGQVwAHMKqHdJje1VTWpljG0WYpCDhrCdAOYH4TWg==}
     engines: {node: '>= 10.x'}
 
+  stackback@0.0.2:
+    resolution: {integrity: sha512-1XMJE5fQo1jGH6Y/7ebnwPOBEkIEnT4QF32d5R1+VXdXveM0IBMJt8zfaxX1P3QhVwrYe+576+jkANtSS2mBbw==}
+
   statuses@2.0.2:
     resolution: {integrity: sha512-DvEy55V3DB7uknRo+4iOGT5fP1slR8wQohVdknigZPMpMstaKJQWhwiYBACJE3Ul2pTnATihhBYnRhZQHGBiRw==}
     engines: {node: '>= 0.8'}
 
+  std-env@4.1.0:
+    resolution: {integrity: sha512-Rq7ybcX2RuC55r9oaPVEW7/xu3tj8u4GeBYHBWCychFtzMIr86A7e3PPEBPT37sHStKX3+TiX/Fr/ACmJLVlLQ==}
+
   string-argv@0.3.2:
     resolution: {integrity: sha512-aqD2Q0144Z+/RqG52NeHEkZauTAUWJO8c6yTftGJKO3Tja5tUgIfmIl6kExvhtxSDP7fXB6DvzkfMpCd/F3G+Q==}
     engines: {node: '>=0.6.19'}
@@ -2966,10 +3038,21 @@ packages:
   tiny-invariant@1.3.3:
     resolution: {integrity: sha512-+FbBPE1o9QAYvviau/qC5SE3caw21q3xkvWKBtja5vgqOWIHHJ3ioaq1VPfn/Szqctz2bU/oYeKd9/z5BL+PVg==}
 
+  tinybench@2.9.0:
+    resolution: {integrity: sha512-0+DUvqWMValLmha6lr4kD8iAMK1HzV0/aKnCtWb9v9641TnP/MFb7Pc2bxoxQjTXAErryXVgUOfv2YqNllqGeg==}
+
+  tinyexec@1.2.4:
+    resolution: {integrity: sha512-SHf/r48b7vOrjve9PxJo3MN5v5yuyjHvdUcrQffT3WXMUfnGmHDVbC4k3sHJaJTgZCwpUplIaAo5ANtMyp3YHg==}
+    engines: {node: '>=18'}
+
   tinyglobby@0.2.16:
     resolution: {integrity: sha512-pn99VhoACYR8nFHhxqix+uvsbXineAasWm5ojXoN8xEwK5Kd3/TrhNn1wByuD52UxWRLy8pu+kRMniEi6Eq9Zg==}
     engines: {node: '>=12.0.0'}
 
+  tinyrainbow@3.1.0:
+    resolution: {integrity: sha512-Bf+ILmBgretUrdJxzXM0SgXLZ3XfiaUuOj/IKQHuTXip+05Xn+uyEYdVg0kYDipTBcLrCVyUzAPz7QmArb0mmw==}
+    engines: {node: '>=14.0.0'}
+
   to-regex-range@5.0.1:
     resolution: {integrity: sha512-65P7iz6X5yEr1cwcgvQxbbIw7Uk3gOy5dIdtZ4rDveLqhrdJP+Li/Hx6tyK0NEb+2GCyneCMJiGqrADCSNk8sQ==}
     engines: {node: '>=8.0'}
@@ -3136,11 +3219,56 @@ packages:
       yaml:
         optional: true
 
+  vitest@4.1.8:
+    resolution: {integrity: sha512-flY6ScbCIt9HThs+C5HS7jvGOB560DJtk/Z15IQROTA6zEy49Nh8T/dofWTQL+n3vswqn87sbJNiuqw1SDp5Ig==}
+    engines: {node: ^20.0.0 || ^22.0.0 || >=24.0.0}
+    hasBin: true
+    peerDependencies:
+      '@edge-runtime/vm': '*'
+      '@opentelemetry/api': ^1.9.0
+      '@types/node': ^20.0.0 || ^22.0.0 || >=24.0.0
+      '@vitest/browser-playwright': 4.1.8
+      '@vitest/browser-preview': 4.1.8
+      '@vitest/browser-webdriverio': 4.1.8
+      '@vitest/coverage-istanbul': 4.1.8
+      '@vitest/coverage-v8': 4.1.8
+      '@vitest/ui': 4.1.8
+      happy-dom: '*'
+      jsdom: '*'
+    peerDependenciesMeta:
+      '@edge-runtime/vm':
+        optional: true
+      '@opentelemetry/api':
+        optional: true
+      '@types/node':
+        optional: true
+      '@vitest/browser-playwright':
+        optional: true
+      '@vitest/browser-preview':
+        optional: true
+      '@vitest/browser-webdriverio':
+        optional: true
+      '@vitest/coverage-istanbul':
+        optional: true
+      '@vitest/coverage-v8':
+        optional: true
+      '@vitest/ui':
+        optional: true
+      happy-dom:
+        optional: true
+      jsdom:
+        optional: true
+
   which@2.0.2:
     resolution: {integrity: sha512-BLI3Tl1TW3Pvl70l3yq3Y64i+awpwXqsGBYWkkqMtnbXgrMD+yj7rhW0kuEDxzJaYXGjEW5ogapKNMEKNMjibA==}
     engines: {node: '>= 8'}
     hasBin: true
 
+  why-is-node-running@2.3.0:
+    resolution: {integrity: sha512-hUrmaWBdVDcxvYqnyh09zunKzROWjbZTiNy8dBEjkS7ehEDQibXJ7XvlmtbwuTclUiIyN+CyXQD4Vmko8fNm8w==}
+    engines: {node: '>=8'}
+    hasBin: true
+
   wouter@3.10.0:
     resolution: {integrity: sha512-zTfddD80zc2/J5l8JKcdvzOK6AwP0kpyHEI3DxRN2bn8U1oJPnrSVm8v+X3WwDamvLAOxTO7ZvkxkpRWlyeJ1Q==}
     peerDependencies:
@@ -4245,6 +4373,8 @@ snapshots:
 
   '@sindresorhus/merge-streams@4.0.0': {}
 
+  '@standard-schema/spec@1.1.0': {}
+
   '@tabby_ai/hijri-converter@1.0.5': {}
 
   '@tailwindcss/node@4.3.0':
@@ -4313,6 +4443,11 @@ snapshots:
       '@types/connect': 3.4.38
       '@types/node': 25.6.2
 
+  '@types/chai@5.2.3':
+    dependencies:
+      '@types/deep-eql': 4.0.2
+      assertion-error: 2.0.1
+
   '@types/connect@3.4.38':
     dependencies:
       '@types/node': 25.6.2
@@ -4349,6 +4484,8 @@ snapshots:
 
   '@types/d3-timer@3.0.2': {}
 
+  '@types/deep-eql@4.0.2': {}
+
   '@types/estree@1.0.8': {}
 
   '@types/express-serve-static-core@5.1.1':
@@ -4415,6 +4552,47 @@ snapshots:
     transitivePeerDependencies:
       - supports-color
 
+  '@vitest/expect@4.1.8':
+    dependencies:
+      '@standard-schema/spec': 1.1.0
+      '@types/chai': 5.2.3
+      '@vitest/spy': 4.1.8
+      '@vitest/utils': 4.1.8
+      chai: 6.2.2
+      tinyrainbow: 3.1.0
+
+  '@vitest/mocker@4.1.8(vite@7.3.3(@types/node@25.6.2)(jiti@2.7.0)(lightningcss@1.32.0)(tsx@4.21.0)(yaml@2.8.4))':
+    dependencies:
+      '@vitest/spy': 4.1.8
+      estree-walker: 3.0.3
+      magic-string: 0.30.21
+    optionalDependencies:
+      vite: 7.3.3(@types/node@25.6.2)(jiti@2.7.0)(lightningcss@1.32.0)(tsx@4.21.0)(yaml@2.8.4)
+
+  '@vitest/pretty-format@4.1.8':
+    dependencies:
+      tinyrainbow: 3.1.0
+
+  '@vitest/runner@4.1.8':
+    dependencies:
+      '@vitest/utils': 4.1.8
+      pathe: 2.0.3
+
+  '@vitest/snapshot@4.1.8':
+    dependencies:
+      '@vitest/pretty-format': 4.1.8
+      '@vitest/utils': 4.1.8
+      magic-string: 0.30.21
+      pathe: 2.0.3
+
+  '@vitest/spy@4.1.8': {}
+
+  '@vitest/utils@4.1.8':
+    dependencies:
+      '@vitest/pretty-format': 4.1.8
+      convert-source-map: 2.0.0
+      tinyrainbow: 3.1.0
+
   accepts@2.0.0:
     dependencies:
       mime-types: 3.0.2
@@ -4447,6 +4625,8 @@ snapshots:
     dependencies:
       tslib: 2.8.1
 
+  assertion-error@2.0.1: {}
+
   atomic-sleep@1.0.0: {}
 
   balanced-match@4.0.4: {}
@@ -4497,6 +4677,8 @@ snapshots:
 
   caniuse-lite@1.0.30001792: {}
 
+  chai@6.2.2: {}
+
   chokidar@4.0.3:
     dependencies:
       readdirp: 4.1.2
@@ -4685,6 +4867,8 @@ snapshots:
 
   es-errors@1.3.0: {}
 
+  es-module-lexer@2.1.0: {}
+
   es-object-atoms@1.1.1:
     dependencies:
       es-errors: 1.3.0
@@ -4705,6 +4889,10 @@ snapshots:
 
   escape-html@1.0.3: {}
 
+  estree-walker@3.0.3:
+    dependencies:
+      '@types/estree': 1.0.8
+
   esutils@2.0.3: {}
 
   etag@1.8.1: {}
@@ -4726,6 +4914,8 @@ snapshots:
       strip-final-newline: 4.0.0
       yoctocolors: 2.1.2
 
+  expect-type@1.3.0: {}
+
   express@5.2.1:
     dependencies:
       accepts: 2.0.0
@@ -5071,6 +5261,8 @@ snapshots:
 
   object-inspect@1.13.4: {}
 
+  obug@2.1.2: {}
+
   on-exit-leak-free@2.1.2: {}
 
   on-finished@2.4.1:
@@ -5494,6 +5686,8 @@ snapshots:
       side-channel-map: 1.0.1
       side-channel-weakmap: 1.0.2
 
+  siginfo@2.0.0: {}
+
   signal-exit@4.1.0: {}
 
   slash@5.1.0: {}
@@ -5511,8 +5705,12 @@ snapshots:
 
   split2@4.2.0: {}
 
+  stackback@0.0.2: {}
+
   statuses@2.0.2: {}
 
+  std-env@4.1.0: {}
+
   string-argv@0.3.2: {}
 
   strip-ansi@6.0.1:
@@ -5539,11 +5737,17 @@ snapshots:
 
   tiny-invariant@1.3.3: {}
 
+  tinybench@2.9.0: {}
+
+  tinyexec@1.2.4: {}
+
   tinyglobby@0.2.16:
     dependencies:
       fdir: 6.5.0(picomatch@4.0.4)
       picomatch: 4.0.4
 
+  tinyrainbow@3.1.0: {}
+
   to-regex-range@5.0.1:
     dependencies:
       is-number: 7.0.0
@@ -5673,10 +5877,52 @@ snapshots:
       tsx: 4.21.0
       yaml: 2.8.4
 
+  vitest@4.1.8(@types/node@25.6.2)(jiti@2.7.0)(lightningcss@1.32.0)(tsx@4.21.0)(yaml@2.8.4):
+    dependencies:
+      '@vitest/expect': 4.1.8
+      '@vitest/mocker': 4.1.8(vite@7.3.3(@types/node@25.6.2)(jiti@2.7.0)(lightningcss@1.32.0)(tsx@4.21.0)(yaml@2.8.4))
+      '@vitest/pretty-format': 4.1.8
+      '@vitest/runner': 4.1.8
+      '@vitest/snapshot': 4.1.8
+      '@vitest/spy': 4.1.8
+      '@vitest/utils': 4.1.8
+      es-module-lexer: 2.1.0
+      expect-type: 1.3.0
+      magic-string: 0.30.21
+      obug: 2.1.2
+      pathe: 2.0.3
+      picomatch: 4.0.4
+      std-env: 4.1.0
+      tinybench: 2.9.0
+      tinyexec: 1.2.4
+      tinyglobby: 0.2.16
+      tinyrainbow: 3.1.0
+      vite: 7.3.3(@types/node@25.6.2)(jiti@2.7.0)(lightningcss@1.32.0)(tsx@4.21.0)(yaml@2.8.4)
+      why-is-node-running: 2.3.0
+    optionalDependencies:
+      '@types/node': 25.6.2
+    transitivePeerDependencies:
+      - jiti
+      - less
+      - lightningcss
+      - msw
+      - sass
+      - sass-embedded
+      - stylus
+      - sugarss
+      - terser
+      - tsx
+      - yaml
+
   which@2.0.2:
     dependencies:
       isexe: 2.0.0
 
+  why-is-node-running@2.3.0:
+    dependencies:
+      siginfo: 2.0.0
+      stackback: 0.0.2
+
   wouter@3.10.0(react@19.1.0):
     dependencies:
       mitt: 3.0.1