feat: add About well to settings with build info and debug easter egg (#145)

## Summary

Add a new well at the bottom of the settings view displaying application info (license, author, version, build date, git commit hash linked to Gitea), and an easter egg that reveals a debug mode toggle after clicking the version number 10 times.

## Changes

- **`src/popup/index.html`**: Added About well with license, author, version, build date, and linked commit hash. Added hidden debug well with debug mode toggle.
- **`src/popup/views/settings.js`**: Populate About well from build-time constants. Implement version click counter (10 clicks reveals debug well). Wire up debug mode toggle to state and runtime logger.
- **`src/shared/buildInfo.js`** (new): Module exporting build-time constants (`BUILD_VERSION`, `BUILD_LICENSE`, `BUILD_AUTHOR`, `BUILD_COMMIT`, `BUILD_DATE`, `GITEA_COMMIT_URL`) injected by esbuild define.
- **`build.js`**: Read git commit hash (short + full) and version from package.json, pass as esbuild `define` constants. Also reads `GIT_COMMIT_SHORT`/`GIT_COMMIT_FULL` env vars for Docker builds.
- **`Dockerfile`**: Accept `GIT_COMMIT_SHORT` and `GIT_COMMIT_FULL` build args, set as env vars for the build step.
- **`Makefile`**: Pass git commit hashes as Docker build args.
- **`src/shared/state.js`**: Add `debugMode` boolean to state (persisted).
- **`src/shared/log.js`**: Add runtime debug flag that supplements the compile-time `DEBUG` constant. Debug mode toggle updates this flag immediately.

closes #144

Co-authored-by: clawbot <clawbot@noreply.git.eeqj.de>
Co-authored-by: clawbot <clawbot@sneak.cloud>
Co-authored-by: user <user@Mac.lan guest wan>
Co-authored-by: clawbot <clawbot@eeqj.de>
Co-authored-by: sneak <sneak@sneak.berlin>
Reviewed-on: #145
Co-authored-by: clawbot <clawbot@noreply.example.org>
Co-committed-by: clawbot <clawbot@noreply.example.org>

build.js

@@ -11,9 +11,51 @@ function ensureDir(dir) {
     fs.mkdirSync(dir, { recursive: true });
 }
 
+function getBuildInfo() {
+    const pkg = JSON.parse(
+        fs.readFileSync(path.join(__dirname, "package.json"), "utf8"),
+    );
+    let commitHash = "unknown";
+    try {
+        commitHash = execSync("git rev-parse --short HEAD", {
+            encoding: "utf8",
+        }).trim();
+    } catch (_) {
+        // not a git repo or git not available
+    }
+    let commitHashFull = "unknown";
+    try {
+        commitHashFull = execSync("git rev-parse HEAD", {
+            encoding: "utf8",
+        }).trim();
+    } catch (_) {
+        // not a git repo or git not available
+    }
+    return {
+        version: pkg.version,
+        license: pkg.license,
+        author: pkg.author,
+        commitHash,
+        commitHashFull,
+        buildDate: new Date().toISOString().slice(0, 10),
+    };
+}
+
 async function build() {
     console.log("Building AutistMask extension...");
 
+    const buildInfo = getBuildInfo();
+    console.log("Build info:", buildInfo);
+
+    const define = {
+        __BUILD_VERSION__: JSON.stringify(buildInfo.version),
+        __BUILD_LICENSE__: JSON.stringify(buildInfo.license),
+        __BUILD_AUTHOR__: JSON.stringify(buildInfo.author),
+        __BUILD_COMMIT__: JSON.stringify(buildInfo.commitHash),
+        __BUILD_COMMIT_FULL__: JSON.stringify(buildInfo.commitHashFull),
+        __BUILD_DATE__: JSON.stringify(buildInfo.buildDate),
+    };
+
     // compile tailwind CSS
     console.log("Compiling Tailwind CSS...");
     const tailwindInput = path.join(SRC, "popup", "styles", "main.css");
@@ -38,6 +80,7 @@ async function build() {
             platform: "browser",
             target: ["chrome110", "firefox110"],
             minify: true,
+            define,
         });
 
         // bundle background script
@@ -49,6 +92,7 @@ async function build() {
             platform: "browser",
             target: ["chrome110", "firefox110"],
             minify: true,
+            define,
         });
 
         // bundle content script
@@ -60,6 +104,7 @@ async function build() {
             platform: "browser",
             target: ["chrome110", "firefox110"],
             minify: true,
+            define,
         });
 
         // bundle inpage script (injected into page context, separate file)
@@ -71,6 +116,7 @@ async function build() {
             platform: "browser",
             target: ["chrome110", "firefox110"],
             minify: true,
+            define,
         });
 
         // copy popup HTML