Language-aware house style and a resizable chat split

House style now follows the app language: Chinese UI forces the new
bundled humanizer-zh skill into every run, English forces humanizer -
one variant per run, picked by preference with cross-language fallback
so an older catalogue never silently loses house style. Both variants
are protected from grant/revoke, list_skills labels each with its
language, the bundle guard requires both, and startup sync imports the
new skill into existing orgs on next launch. Covered by a unit test
that flips app_state.language and asserts which humanizer compiles.

The chat split is now adjustable: drag the conversation list's right
edge (200-480px, persisted in localStorage) and the composer textarea
grew a native vertical resize grip capped at 40vh.

tests/e2e/builtin-skills-fixture.ts

@@ -14,6 +14,12 @@ export function seedBuiltinSkillsFixture(root: string): string {
     "---\nname: humanizer\nversion: 2.1.1\ndescription: |\n  Remove signs of AI-generated writing from text.\n---\n\nWrite like a person.\n",
     "utf8",
   );
+  mkdirSync(join(root, "Humanizer-zh"), { recursive: true });
+  writeFileSync(
+    join(root, "Humanizer-zh", "SKILL.md"),
+    "---\nname: humanizer-zh\nversion: 1.0.0\ndescription: |\n  去除文本中的 AI 生成痕迹。\n---\n\n像真人一样写作。\n",
+    "utf8",
+  );
   mkdirSync(join(root, "engineering"), { recursive: true });
   writeFileSync(
     join(root, "engineering", "engineering-backend-architect.md"),

tests/e2e/desktop.spec.ts

@@ -182,7 +182,7 @@ test("onboards, hires, and creates work in the Electron shell", async () => {
       const result = await api.loadSnapshot() as { ok: true; data: { skillDefinitions: Array<{ slug: string }> } };
       return result.data.skillDefinitions.map((skill) => skill.slug).sort();
     });
-    expect(skillSlugs).toEqual(["engineering-backend-architect", "humanizer"]);
+    expect(skillSlugs).toEqual(["engineering-backend-architect", "humanizer", "humanizer-zh"]);
 
     // The global pause toggle lives in the topbar on every page.
     const pauseToggle = page.getByRole("button", { name: "Pause agents" });

tests/unit/builtin-skills-bundle.test.ts

@@ -17,6 +17,7 @@ describe("bundled skill catalogue", () => {
       const staged = stageBuiltinSkillsLibrary(resolve(process.cwd(), "built-in skills"), libraryRoot);
       expect(staged.length).toBeGreaterThan(200);
       expect(staged.some((unit) => unit.slug === "humanizer")).toBe(true);
+      expect(staged.some((unit) => unit.slug === "humanizer-zh")).toBe(true);
       const withDescription = staged.filter((unit) => unit.manifest.description).length;
       expect(withDescription / staged.length).toBeGreaterThan(0.9);
     } finally {

tests/unit/builtin-skills.test.ts

@@ -55,6 +55,12 @@ function harness(): Harness {
   mkdirSync(join(sourceRoot, "humanizer"), { recursive: true });
   writeFileSync(join(sourceRoot, "humanizer", "SKILL.md"), HUMANIZER_MD, "utf8");
   writeFileSync(join(sourceRoot, "humanizer", "README.md"), "# About\n", "utf8");
+  mkdirSync(join(sourceRoot, "Humanizer-zh"), { recursive: true });
+  writeFileSync(
+    join(sourceRoot, "Humanizer-zh", "SKILL.md"),
+    "---\nname: humanizer-zh\ndescription: 去除文本中的 AI 生成痕迹。\n---\n\n像真人一样写作。\n",
+    "utf8",
+  );
   mkdirSync(join(sourceRoot, "engineering"), { recursive: true });
   writeFileSync(join(sourceRoot, "engineering", "engineering-backend-architect.md"), ARCHITECT_MD, "utf8");
   writeFileSync(join(sourceRoot, "engineering", "README.md"), "docs, not a skill\n", "utf8");
@@ -75,8 +81,9 @@ describe("built-in skills", () => {
   test("stages both bundle shapes into the library and imports them once per org", () => {
     const h = harness();
     const staged = stageBuiltinSkillsLibrary(h.sourceRoot, h.libraryRoot);
-    expect(staged.map((unit) => unit.slug).sort()).toEqual(["engineering-backend-architect", "humanizer"]);
+    expect(staged.map((unit) => unit.slug).sort()).toEqual(["engineering-backend-architect", "humanizer", "humanizer-zh"]);
     expect(existsSync(join(h.libraryRoot, "humanizer", "SKILL.md"))).toBe(true);
+    expect(existsSync(join(h.libraryRoot, "humanizer-zh", "SKILL.md"))).toBe(true);
     expect(existsSync(join(h.libraryRoot, "engineering-backend-architect", "SKILL.md"))).toBe(true);
     const architect = staged.find((unit) => unit.slug === "engineering-backend-architect");
     expect(architect?.manifest.name).toBe("Backend Architect");
@@ -86,12 +93,12 @@ describe("built-in skills", () => {
     expect(humanizer?.manifest.description).toContain("AI-generated writing");
 
     const first = h.connection.transaction(() => importStagedSkills(h.skills, h.orgId, staged));
-    expect(first).toMatchObject({ imported: 2, skipped: 0, retired: 0, failures: [] });
+    expect(first).toMatchObject({ imported: 3, skipped: 0, retired: 0, failures: [] });
     const second = h.connection.transaction(() => importStagedSkills(h.skills, h.orgId, staged));
-    expect(second).toMatchObject({ imported: 0, skipped: 2, retired: 0 });
+    expect(second).toMatchObject({ imported: 0, skipped: 3, retired: 0 });
     const slugs = (h.connection.db.prepare("select slug from skill_definitions where org_id = ? order by slug").all(h.orgId) as Array<{ slug: string }>)
       .map((row) => row.slug);
-    expect(slugs).toEqual(["engineering-backend-architect", "humanizer"]);
+    expect(slugs).toEqual(["engineering-backend-architect", "humanizer", "humanizer-zh"]);
     h.connection.close();
   });
 
@@ -191,6 +198,43 @@ describe("built-in skills", () => {
     h.connection.close();
   });
 
+  test("the forced humanizer follows the app language, with cross-language fallback", () => {
+    const h = harness();
+    const staged = stageBuiltinSkillsLibrary(h.sourceRoot, h.libraryRoot);
+    h.connection.transaction(() => importStagedSkills(h.skills, h.orgId, staged));
+    let agentId = "";
+    h.connection.transaction(() => {
+      agentId = h.organization.createAgent({
+        orgId: h.orgId, name: "Ada", role: "Engineer", department: "Engineering",
+        modelProviderId: null, modelId: null, budgetCents: 1000, managerAgentId: null,
+      });
+    });
+    const promptFor = (runId: string) => {
+      const snapshotId = h.connection.transaction(() => h.skills.resolveRuntimeSnapshot({ orgId: h.orgId, agentId, runId }));
+      return (h.connection.db.prepare("select compiled_prompt from skill_runtime_snapshots where id = ?").get(snapshotId) as { compiled_prompt: string }).compiled_prompt;
+    };
+
+    // English UI (default): the English humanizer, and only that one.
+    const englishPrompt = promptFor("run_lang_en");
+    expect(englishPrompt).toContain("# Skill: humanizer");
+    expect(englishPrompt).not.toContain("humanizer-zh");
+
+    // Chinese UI: the Chinese variant replaces it.
+    h.connection.transaction(() => h.organization.updateUiPreferences({ language: "zh" }));
+    const chinesePrompt = promptFor("run_lang_zh");
+    expect(chinesePrompt).toContain("# Skill: humanizer-zh");
+    expect(chinesePrompt).not.toContain("# Skill: humanizer\n");
+
+    // Chinese UI against a catalogue without the zh variant falls back to
+    // English house style instead of silently dropping it.
+    h.connection.transaction(() => {
+      h.connection.db.prepare("update skill_definitions set status = 'retired' where org_id = ? and slug = 'humanizer-zh'").run(h.orgId);
+    });
+    const fallbackPrompt = promptFor("run_lang_fallback");
+    expect(fallbackPrompt).toContain("# Skill: humanizer");
+    h.connection.close();
+  });
+
   test("frontmatter parsing reads inline values and block scalars", () => {
     expect(parseFrontmatter(ARCHITECT_MD)).toMatchObject({
       name: "Backend Architect",

tests/unit/skill-grants.test.ts

@@ -68,6 +68,10 @@ function importSkill(h: Harness, name: string, slug: string): void {
     insert into skill_revisions(id, skill_id, version_semver, manifest_json, source_type, source_ref, published_at, immutable_checksum)
     values (?, ?, '1.0.0', '{}', 'local_directory', '/tmp', ?, 'checksum')
   `).run(`skr_${slug}`, `skl_${slug}`, now);
+  h.connection.db.prepare(`
+    insert into skill_artifacts(id, revision_id, artifact_type, object_key, sha256, size_bytes)
+    values (?, ?, 'entrypoint', ?, 'sha', 1)
+  `).run(`ska_${slug}`, `skr_${slug}`, `/tmp/${slug}/SKILL.md`);
 }
 
 describe("skill grants", () => {