feat: stuffy feature bundle (#159)

## Summary

This PR bundles a collection of new features and quality-of-life improvements identified during a Claude CLI 2.1.50 audit.

- **Tab status indicator** — Tab stays yellow until the greeting is responded to, then turns green. Fixed disconnect not resetting to grey. Closes #157
- **Auth status display** — New "Account" section in settings sidebar showing login status, email, org, API key source, and Hikari override indicator. Includes login/logout buttons. Closes #153
- **CLI version badge** — New "Supported" badge showing the highest audited CLI version, colour-coded green/amber/red based on installed vs supported version. Closes #154 (bump to 2.1.50)
- **Rate limit events** — `rate_limit_event` messages from the stream are now parsed and shown as amber `[rate-limit]` lines in the terminal instead of being silently dropped. Closes #155
- **"Prompt is too long" handling** — Detects this error in assistant messages and shows a ⚡ Compact Conversation button to send `/compact` directly. Closes #158
- **`last_assistant_message` in Agent Monitor** — Extracts the agent's final output from the `ToolResult` content block in the JSON stream and displays it as a snippet on completed agent cards. Closes #156
- **`--worktree` flag** — New "Worktree isolation" toggle in session settings passes `--worktree` to Claude Code. Hook events (`WorktreeCreate`/`WorktreeRemove`) are displayed as green `[worktree]` lines. Closes #152, Closes #150
- **ConfigChange hook events** — `[ConfigChange Hook]` stderr events are now displayed as cyan `[config]` lines instead of errors. Closes #151
- **`CLAUDE_CODE_DISABLE_1M_CONTEXT` toggle** — New "Disable 1M context" setting in session configuration injects this env var into the Claude process. Closes #154

## Test plan

- [ ] Tab status indicator: start a new session and verify the tab stays yellow until Claude responds to the greeting, then turns green
- [ ] Auth status: open settings and verify the Account section shows correct login info
- [ ] CLI version badge: verify the "Supported 2.1.50" badge shows green when CLI matches
- [ ] Rate limit events: unit tests cover parsing; amber `[rate-limit]` lines display correctly
- [ ] Compact button: unit tests cover detection; button renders correctly in terminal
- [ ] Agent Monitor: use the Task tool and verify completed agent cards show a message snippet
- [ ] Worktree: enable toggle, start session, verify `--worktree` flag appears in process args
- [ ] ConfigChange: hook events display as `[config]` lines rather than errors
- [ ] Disable 1M context: enable toggle, start session, verify `CLAUDE_CODE_DISABLE_1M_CONTEXT=1` in `/proc/<pid>/environ`

✨ This PR was created with help from Hikari~ 🌸

Reviewed-on: #159
Co-authored-by: Hikari <hikari@nhcarrigan.com>
Co-committed-by: Hikari <hikari@nhcarrigan.com>

src/lib/components/StatusBar.svelte

@@ -101,6 +101,8 @@
     budget_warning_threshold: 0.8,
     discord_rpc_enabled: true,
     show_thinking_blocks: true,
+    use_worktree: false,
+    disable_1m_context: false,
   });
 
   let streamerModeActive = $state(false);
@@ -178,6 +180,8 @@
           custom_instructions: currentConfig.custom_instructions || null,
           mcp_servers_json: currentConfig.mcp_servers_json || null,
           allowed_tools: allAllowedTools,
+          use_worktree: currentConfig.use_worktree ?? false,
+          disable_1m_context: currentConfig.disable_1m_context ?? false,
         },
       });
 
@@ -289,6 +293,8 @@
           custom_instructions: currentConfig.custom_instructions || null,
           mcp_servers_json: currentConfig.mcp_servers_json || null,
           allowed_tools: allAllowedTools,
+          use_worktree: currentConfig.use_worktree ?? false,
+          disable_1m_context: currentConfig.disable_1m_context ?? false,
         },
       });