Add copy-only, color swatches, DB speed pragmas, and living docs

- Copy only (right-click -> Copy): write to clipboard without
  auto-pasting or hiding the window
- Color swatches: hex/rgb/hsl entries show a preview chip
- SQLite WAL + synchronous=NORMAL so the UI can read while the
  clipboard poller writes
- Memoize list rows (React.memo) so selection/focus changes don't
  re-render every row's preview
- Add docs/GUIDE.md (living install + usage doc), docs/SHARING.md,
  docs/TESTING.md, docs/LAUNCH-AT-LOGIN.md, docs/PRODUCT.md,
  CHANGELOG.md, ROADMAP.md
- Add homelab Gitea Actions CI (.gitea/workflows/ci.yml) + gitleaks
  allowlist
- Bump version to 0.2.0

src-tauri/tauri.conf.json

@@ -1,7 +1,7 @@
 {
   "$schema": "https://raw.githubusercontent.com/tauri-apps/tauri/dev/crates/tauri-config-schema/schema.json",
   "productName": "maCopy",
-  "version": "0.1.0",
+  "version": "0.2.0",
   "identifier": "com.macopy.app",
   "build": {
     "frontendDist": "../dist",
@@ -43,6 +43,7 @@
             "core:window:allow-set-focus",
             "core:window:allow-close",
             "core:window:allow-is-visible",
+            "core:window:allow-is-focused",
             "core:window:allow-set-size",
             "core:window:allow-set-position",
             "core:window:allow-inner-size",