feat: productivity suite — task loop, workflow, theming, docs & more (#197)

## Summary

A large productivity-focused feature branch delivering a suite of improvements across automation, project management, theming, performance, and documentation.

### Features

- **Guided Project Workflow** (#189) — Four-phase workflow panel (Discuss → Plan → Execute → Verify) to keep projects structured from idea to completion
- **Automated Task Loop** (#179) — Per-task conversation orchestration with wave-based parallel execution, blocked-task detection, and concurrency control
- **Wave-Based Parallel Execution** (#191) — Tasks run in dependency-aware waves with configurable concurrency; independent tasks execute in parallel
- **Auto-Commit After Task Completion** (#192) — Task Loop optionally commits after each completed task so progress is never lost
- **PRD Creator** (#180) — AI-assisted PRD and task list panel that outputs `hikari-tasks.json` for the Task Loop to consume
- **Project Context Panel** (#188) — Persistent `PROJECT.md`, `REQUIREMENTS.md`, `ROADMAP.md`, and `STATE.md` files injected into Claude's context automatically
- **Codebase Mapper** (#190) — Generates a `CODEBASE.md` architectural summary so Claude always understands the project structure
- **Community Preset Themes** (#181) — Six built-in community themes: Dracula, Catppuccin Mocha, Nord, Solarized Dark, Gruvbox Dark, and Rosé Pine
- **In-App Changelog Panel** (#193) — Fetches release notes from GitHub at runtime and displays them inside the app
- **Full Embedded Documentation** (#196) — Replaced the single-page help modal with a 12-page paginated docs browser featuring a sidebar TOC, prev/next navigation, keyboard navigation (arrow keys, `?` shortcut), and comprehensive coverage of every feature

### Performance & Fixes

- **Lazy Loading & Virtualisation** (#194) — Virtual windowing for conversation history, markdown memoisation, and debounced search for smooth rendering of large sessions
- **Ctrl+C Copy Fix** (#195) — `Ctrl+C` now copies selected text as expected; interrupt-Claude behaviour only fires when no text is selected

### UX

- Back-to-workflow button in PRD Creator and Task Loop panels for easy navigation
- Navigation icon cluster replaced with a single clean dropdown menu

## Closes

Closes #179
Closes #180
Closes #181
Closes #188
Closes #189
Closes #190
Closes #191
Closes #192
Closes #193
Closes #194
Closes #195
Closes #196

---

✨ This PR was created with help from Hikari~ 🌸

Reviewed-on: #197
Co-authored-by: Hikari <hikari@nhcarrigan.com>
Co-committed-by: Hikari <hikari@nhcarrigan.com>

src/lib/components/docs/DocsFileEditor.svelte

@@ -0,0 +1,79 @@
+<h3 class="text-lg font-semibold text-[var(--text-primary)] mb-4">File Editor</h3>
+
+<div class="space-y-4 text-sm text-[var(--text-secondary)]">
+  <p>
+    The built-in file editor lets you read and edit project files directly in Hikari Desktop,
+    alongside your conversation. Open it via <strong>File Editor</strong> in the menu or press
+    <kbd class="kbd">Ctrl+E</kbd> (requires an active connection).
+  </p>
+
+  <div>
+    <h4 class="font-medium text-[var(--text-primary)] mb-2">File Browser</h4>
+    <p>
+      The file browser panel (toggle with <kbd class="kbd">Ctrl+B</kbd>) shows your working
+      directory tree. From it you can:
+    </p>
+    <ul class="space-y-1 mt-2">
+      <li>• Click a file to open it in a new editor tab</li>
+      <li>• Right-click for context menu options (rename, delete)</li>
+      <li>• Press <kbd class="kbd">Ctrl+N</kbd> to create a new file</li>
+    </ul>
+  </div>
+
+  <div>
+    <h4 class="font-medium text-[var(--text-primary)] mb-2">Editor Tabs</h4>
+    <p>Each open file gets its own tab. You can have multiple files open at once.</p>
+    <ul class="space-y-1 mt-2">
+      <li>• Click a tab to switch to that file</li>
+      <li>• Click <strong>×</strong> on a tab to close it (<kbd class="kbd">Ctrl+W</kbd>)</li>
+      <li>• Unsaved changes are indicated with a dot on the tab</li>
+      <li>• Press <kbd class="kbd">Ctrl+S</kbd> to save the current file</li>
+    </ul>
+  </div>
+
+  <div>
+    <h4 class="font-medium text-[var(--text-primary)] mb-2">Syntax Highlighting</h4>
+    <p>
+      The editor automatically applies syntax highlighting for a wide range of languages, including:
+    </p>
+    <p class="mt-1">
+      JavaScript · TypeScript · Python · Rust · Go · Java · C++ · HTML · CSS · JSON · YAML ·
+      Markdown · SQL · Shell · PHP · Ruby · Swift · R · TOML · Dockerfile · PowerShell
+    </p>
+    <p class="mt-2">
+      The editor theme follows your app theme — dark themes use dark editor backgrounds.
+    </p>
+  </div>
+
+  <div>
+    <h4 class="font-medium text-[var(--text-primary)] mb-2">Editor Features</h4>
+    <ul class="space-y-1">
+      <li>• Line numbers, bracket matching, and code folding</li>
+      <li>• Search and replace (<kbd class="kbd">Ctrl+F</kbd> in most editors)</li>
+      <li>• Right-click context menu for common operations</li>
+      <li>• Full CodeMirror keybindings</li>
+    </ul>
+  </div>
+
+  <div>
+    <h4 class="font-medium text-[var(--text-primary)] mb-2">Working with Hikari</h4>
+    <p>
+      Hikari can read and edit files directly through her tool access — you don't need the file
+      editor open for her to work on files. The editor is most useful for reviewing changes she's
+      made, manually editing files alongside the conversation, or browsing the project structure.
+    </p>
+  </div>
+</div>
+
+<style>
+  kbd.kbd {
+    display: inline-block;
+    padding: 0.1rem 0.35rem;
+    font-size: 0.75rem;
+    font-family: monospace;
+    background: var(--bg-secondary);
+    border: 1px solid var(--border-color);
+    border-radius: 3px;
+    color: var(--text-primary);
+  }
+</style>