Fix subagent crash and add external OpenCode server support (#188)

* 🐛 Fix UI crash when subagent is active

Remove sessions dependency from hooks to prevent cascading re-renders.
Use getState() instead and switch to getGlobalSessionStatus().

* ✨ Add support for connecting to external OpenCode server

Add OPENCODE_SKIP_START env var to skip starting embedded server.
Use OPENCODE_PORT to connect to existing OpenCode instance.
Update help text to document the new environment variables.

* 📝 Document external OpenCode server support

Add OPENCODE_PORT and OPENCODE_SKIP_START to READMEs.
Update AGENTS.md with external server integration notes.

* ✨ Add URL-based routing for shareable session links

- Add react-router-dom dependency
- Create URL store for bi-directional sync with Zustand
- Add WebRouter/DesktopRouter context for runtime-aware routing
- Add useURLSync hook to sync URL with session/tab state
- Add useNavigation hook with copySessionLink utility
- Add share button in Header for copying session links
- Update App.tsx to use router wrappers

URL structure:
  /session/:sessionId?tab={chat|git|diff|terminal|files}&directory=/path
  /settings

This enables shareable links and deep-linking to specific sessions.

* Revert "✨ Add URL-based routing for shareable session links"

This reverts commit b53ee304950a789538fa3d4a236d6361e634ea61.

packages/web/bin/cli.js

@@ -153,7 +153,7 @@ function parseArgs() {
 
 function showHelp() {
   console.log(`
-OpenChamber - Web interface for the OpenCode AI coding agent
+ OpenChamber - Web interface for the OpenCode AI coding agent
 
 USAGE:
   openchamber [COMMAND] [OPTIONS]
@@ -176,7 +176,9 @@ OPTIONS:
   -v, --version           Show version
 
 ENVIRONMENT:
-  OPENCHAMBER_UI_PASSWORD  Alternative to --ui-password flag
+  OPENCHAMBER_UI_PASSWORD      Alternative to --ui-password flag
+  OPENCODE_PORT               Port of external OpenCode server to connect to
+  OPENCODE_SKIP_START          Skip starting OpenCode, use external server
 
 EXAMPLES:
   openchamber                    # Start on default port 3000 (or a free port)
@@ -506,6 +508,7 @@ const commands = {
           OPENCODE_BINARY: opencodeBinary,
           ...(typeof effectiveUiPassword === 'string' ? { OPENCHAMBER_UI_PASSWORD: effectiveUiPassword } : {}),
           OPENCHAMBER_TRY_CF_TUNNEL: options.tryCfTunnel ? 'true' : 'false',
+          ...(process.env.OPENCODE_SKIP_START ? { OPENCHAMBER_SKIP_OPENCODE_START: process.env.OPENCODE_SKIP_START } : {}),
         }
       });
 
@@ -574,6 +577,9 @@ const commands = {
     if (typeof effectiveUiPassword === 'string') {
       process.env.OPENCHAMBER_UI_PASSWORD = effectiveUiPassword;
     }
+    if (process.env.OPENCODE_SKIP_START) {
+      process.env.OPENCHAMBER_SKIP_OPENCODE_START = process.env.OPENCODE_SKIP_START;
+    }
     if (showAutoGeneratedPassword) {
       console.log(`\n🔐 Auto-generated password: \x1b[92m${effectiveUiPassword}\x1b[0m`);
       console.log('⚠️  Save this password - it won\'t be shown again!\n');
@@ -590,6 +596,7 @@ const commands = {
           OPENCODE_BINARY: opencodeBinary,
           ...(typeof effectiveUiPassword === 'string' ? { OPENCHAMBER_UI_PASSWORD: effectiveUiPassword } : {}),
           OPENCHAMBER_TRY_CF_TUNNEL: options.tryCfTunnel ? 'true' : 'false',
+          ...(process.env.OPENCODE_SKIP_START ? { OPENCHAMBER_SKIP_OPENCODE_START: process.env.OPENCODE_SKIP_START } : {}),
         },
       });