feat: implement Undo/Redo/Timeline and Fork Features and fixed opencode.json reading issue on broken json (#99)

* feat: add /undo, /redo, /timeline slash commands and fork button

- Add /undo command to revert to previous user message
- Add /redo command to redo previously undone messages
- Add /timeline command to show conversation history
- Add fork button on user messages (hover) to create new session
- Add TimelineDialog component for navigating conversation history
- Show undo/redo/timeline in autocomplete when session exists
- Fix fork to use SDK session.fork API
- Silent no-op behavior for undo/redo when no messages (matches OpenCode CLI)

* fix: correct fork session endpoint and session switching

- Add hybrid SDK approach using v1 for existing methods and v2 for fork only
- v2 SDK has correct endpoint /session/{sessionID}/fork instead of broken /session/{id}/fork
- Fix forkFromMessage to use setCurrentSession instead of direct set
- Ensures both useSessionStore and useSessionManagementStore are consistent
- Fixes issue where forked sessions appeared empty until sending a new message

* fix: use direct fetch for fork to avoid v2 SDK build errors

- Remove v2 SDK imports and hybrid SDK approach
- Use direct fetch() call to /api/session/{sessionID}/fork endpoint
- Avoids type conflicts between v1 and v2 SDK
- Bypasses broken v1 SDK fork endpoint (wrong path parameter)
- All codebase now uses v1 SDK consistently

* fix: use jsonc-parser for config file parsing

- Replace strip-json-comments + JSON.parse with jsonc-parser
- Handles comments, trailing commas, and unquoted keys
- Matches OpenCode CLI config parsing behavior
- Fixes SyntaxError when reading global opencode.json config

* feat: improve timeline dialog with loading state and search

- Add loading spinner on fork button during operation (~30s on big sessions)
- Refresh session list after fork so new session appears in sidebar immediately
- Add search bar to filter messages by prompt text content
- Show 'No messages found' when search has no results
- Disable fork button while forking to prevent duplicate operations

packages/web/package.json

@@ -43,6 +43,7 @@
     "cmdk": "^1.1.1",
     "express": "^5.1.0",
     "http-proxy-middleware": "^3.0.5",
+    "jsonc-parser": "^3.3.1",
     "next-themes": "^0.4.6",
     "bun-pty": "^0.4.5",
     "node-pty": "^1.1.0",

packages/web/server/lib/opencode-config.js

@@ -2,7 +2,7 @@ import fs from 'fs';
 import path from 'path';
 import os from 'os';
 import yaml from 'yaml';
-import stripJsonComments from 'strip-json-comments';
+import { parse as parseJsonc } from 'jsonc-parser';
 
 const OPENCODE_CONFIG_DIR = path.join(os.homedir(), '.config', 'opencode');
 const AGENT_DIR = path.join(OPENCODE_CONFIG_DIR, 'agent');
@@ -431,11 +431,12 @@ function readConfigFile(filePath) {
   }
   try {
     const content = fs.readFileSync(filePath, 'utf8');
-    const normalized = stripJsonComments(content).trim();
+    const normalized = content.trim();
     if (!normalized) {
       return {};
     }
-    return JSON.parse(normalized);
+    // jsonc-parser handles comments, trailing commas, unquoted keys
+    return parseJsonc(normalized, [], { allowTrailingComma: true });
   } catch (error) {
     console.error(`Failed to read config file: ${filePath}`, error);
     throw new Error('Failed to read OpenCode configuration');