feat(app): add persistent project colour tags

bench/baseline/sizes.json

@@ -9,8 +9,8 @@
       "recorded_at": "2026-08-20T20:12:18.316Z"
     },
     "frontend:initial": {
-      "bytes": 845843,
-      "recorded_at": "2026-09-07T14:38:04.389Z"
+      "bytes": 538600,
+      "recorded_at": "2026-09-17T19:06:00.357Z"
     }
   },
   "startup": {

gg-app/README.md

@@ -24,6 +24,19 @@ pnpm --filter gg-app test     # vitest
 pnpm --filter gg-app lint
 ```
 
+## Project colour tags
+
+Click the colour button beside an open project's name to choose a personal colour.
+**Automatic** restores the generated accent; **None** removes the decoration without
+hiding the button. **Show header stripe** adds an app-wide stripe and is off by default.
+None suppresses the stripe for that project.
+
+Choices belong to the full project folder path, so same-named folders stay separate.
+Native windows share preferences in `~/.gg/gg-app-project-colours.json`, independently
+of other app settings. These preferences are personal, survive restarts, and are not
+written into the project or shared with teammates. Browser previews use local storage
+instead; they do not share the native app's preferences.
+
 ## Architecture
 
 Each window runs its **own** Node agent sidecar pointed at its **own** project folder.

gg-app/scripts/markdown-split.test.mjs

@@ -0,0 +1,48 @@
+import { mkdtempSync, readFileSync, rmSync, statSync } from "node:fs";
+import { tmpdir } from "node:os";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import { spawnSync } from "node:child_process";
+import { expect, it } from "vitest";
+
+it("keeps rich-text rendering outside startup and production JS chunks below the warning limit", () => {
+  const out = mkdtempSync(path.join(tmpdir(), "gg-markdown-split-"));
+  try {
+    // Run the installed JS entry with Node, not a platform-specific pnpm shim.
+    const viteCli = fileURLToPath(new URL("../node_modules/vite/bin/vite.js", import.meta.url));
+    const build = spawnSync(
+      process.execPath,
+      [viteCli, "build", "--outDir", out, "--emptyOutDir"],
+      {
+        cwd: fileURLToPath(new URL("../", import.meta.url)),
+        encoding: "utf8",
+        // Vitest sets NODE_ENV=test; measure the shipped React build instead.
+        env: { ...process.env, NODE_ENV: "production" },
+        timeout: 30_000,
+      },
+    );
+    expect(build.error).toBeUndefined();
+    expect(build.status, build.stdout + build.stderr).toBe(0);
+    const manifest = JSON.parse(readFileSync(path.join(out, ".vite/manifest.json"), "utf8"));
+    expect(manifest["src/MarkdownRenderer.tsx"].isDynamicEntry).toBe(true);
+    const initial = new Set();
+    function visit(key) {
+      if (initial.has(key)) return;
+      initial.add(key);
+      for (const imported of manifest[key].imports ?? []) visit(imported);
+    }
+    for (const [key, chunk] of Object.entries(manifest)) if (chunk.isEntry) visit(key);
+    expect(initial.has("src/MarkdownRenderer.tsx")).toBe(false);
+    for (const chunk of Object.values(manifest)) {
+      if (chunk.file.endsWith(".js"))
+        expect(statSync(path.join(out, chunk.file)).size, chunk.file).toBeLessThanOrEqual(500_000);
+    }
+    const initialBytes = [...initial].reduce(
+      (bytes, key) => bytes + statSync(path.join(out, manifest[key].file)).size,
+      0,
+    );
+    expect(initialBytes).toBeLessThan(600_000);
+  } finally {
+    rmSync(out, { recursive: true, force: true });
+  }
+}, 35_000);

gg-app/src-tauri/src/lib.rs

@@ -5,6 +5,8 @@ use std::process::{Child, Command, Stdio};
 use std::sync::atomic::{AtomicBool, AtomicU64, Ordering};
 use std::sync::Mutex;
 
+mod project_colours;
+
 #[cfg(unix)]
 use std::os::unix::process::CommandExt;
 #[cfg(windows)]
@@ -5088,6 +5090,7 @@ pub fn run() {
             ..Default::default()
         })
         .manage(Windows::default())
+        .manage(project_colours::ProjectColours::default())
         .manage(RestoreTargets::default())
         .manage(AppExiting::default())
         .manage(FocusedWindow::default())
@@ -5156,6 +5159,8 @@ pub fn run() {
             agent_set_project_hidden,
             app_settings_get,
             app_settings_save,
+            project_colours::project_colours_get,
+            project_colours::project_colours_save,
             app_create_project,
             app_auth_status,
             app_auth_apikey,