Add VIBETUNNEL_PREFER_DERIVED_DATA support and version tracking

- Add VIBETUNNEL_PREFER_DERIVED_DATA environment variable to vt script
  - When set, prefers VibeTunnel builds from Xcode's DerivedData
  - Logs binary location, version, and build timestamp
  - Falls back to /Applications if no DerivedData build found
- Add version and buildDate to StatusResponse interface
- Include version info in api-socket-server status responses
- Add comprehensive documentation in README.md
- Version info already stored in session.json (was pre-existing)

This helps developers easily test changes without installing to /Applications

README.md

@@ -862,6 +862,35 @@ VIBETUNNEL_DEBUG=1 vt your-command
 
 Debug logs are written to `~/.vibetunnel/log.txt`.
 
+### Using Development Builds with vt
+
+When developing VibeTunnel, you can use the `VIBETUNNEL_PREFER_DERIVED_DATA` environment variable to make the `vt` command prefer development builds from Xcode's DerivedData folder:
+
+```bash
+# Enable DerivedData preference
+export VIBETUNNEL_PREFER_DERIVED_DATA=1
+
+# vt will now search for and use the latest VibeTunnel build from DerivedData
+vt your-command
+```
+
+When this environment variable is set, `vt` will:
+1. First search for VibeTunnel builds in `~/Library/Developer/Xcode/DerivedData`
+2. Use the most recently modified build found there
+3. Fall back to `/Applications/VibeTunnel.app` if no DerivedData build exists
+4. Log the exact binary location, version, and build timestamp being used
+
+This is particularly useful for:
+- Testing changes without installing to `/Applications`
+- Working with multiple VibeTunnel builds simultaneously
+- Quickly switching between development and production versions
+- Debugging which version of VibeTunnel is being used
+
+The version information is also:
+- Stored in `session.json` for each session
+- Displayed in `vt status` output
+- Shown in the initial log output when `VIBETUNNEL_PREFER_DERIVED_DATA` is set
+
 ### Verbosity Control
 
 Control the amount of output from VibeTunnel commands:

web/bin/vt

@@ -20,28 +20,47 @@ if [[ "$OSTYPE" == "darwin"* ]]; then
     # Get the real path of this script to avoid infinite recursion
     SCRIPT_REAL_PATH="$(resolve_symlink_macos "${BASH_SOURCE[0]}")"
 
-    # Comprehensive Mac app search - try standard locations first, then development locations
+    # Comprehensive Mac app search - order depends on VIBETUNNEL_PREFER_DERIVED_DATA
     APP_PATH=""
     
-    # First try standard locations with valid binary check
-    for TRY_PATH in "/Applications/VibeTunnel.app" "$HOME/Applications/VibeTunnel.app"; do
-        if [ -d "$TRY_PATH" ] && [ -f "$TRY_PATH/Contents/Resources/vibetunnel" ]; then
-            VT_SCRIPT="$TRY_PATH/Contents/Resources/vt"
-            if [ -f "$VT_SCRIPT" ] && [ -x "$VT_SCRIPT" ]; then
-                # Avoid infinite recursion by checking if this is the same script
-                VT_REAL_PATH="$(resolve_symlink_macos "$VT_SCRIPT")"
-                if [ "$SCRIPT_REAL_PATH" != "$VT_REAL_PATH" ]; then
-                    exec "$VT_SCRIPT" "$@"
+    if [ -n "$VIBETUNNEL_PREFER_DERIVED_DATA" ]; then
+        # When preference is set, try DerivedData first
+        for CANDIDATE in $(find ~/Library/Developer/Xcode/DerivedData -name "VibeTunnel.app" -type d 2>/dev/null | grep -v "\.dSYM" | grep -v "Index\.noindex" | sort -r); do
+            if [ -f "$CANDIDATE/Contents/Resources/vibetunnel" ]; then
+                VT_SCRIPT="$CANDIDATE/Contents/Resources/vt"
+                if [ -f "$VT_SCRIPT" ] && [ -x "$VT_SCRIPT" ]; then
+                    VT_REAL_PATH="$(resolve_symlink_macos "$VT_SCRIPT")"
+                    if [ "$SCRIPT_REAL_PATH" != "$VT_REAL_PATH" ]; then
+                        exec "$VT_SCRIPT" "$@"
+                    fi
                 fi
+                APP_PATH="$CANDIDATE"
+                break
             fi
-            APP_PATH="$TRY_PATH"
-            break
-        fi
-    done
+        done
+    fi
     
-    # If not found in standard locations, search for development builds
+    # If not found yet, try standard locations
     if [ -z "$APP_PATH" ]; then
-        # First try DerivedData (for development)
+        for TRY_PATH in "/Applications/VibeTunnel.app" "$HOME/Applications/VibeTunnel.app"; do
+            if [ -d "$TRY_PATH" ] && [ -f "$TRY_PATH/Contents/Resources/vibetunnel" ]; then
+                VT_SCRIPT="$TRY_PATH/Contents/Resources/vt"
+                if [ -f "$VT_SCRIPT" ] && [ -x "$VT_SCRIPT" ]; then
+                    # Avoid infinite recursion by checking if this is the same script
+                    VT_REAL_PATH="$(resolve_symlink_macos "$VT_SCRIPT")"
+                    if [ "$SCRIPT_REAL_PATH" != "$VT_REAL_PATH" ]; then
+                        exec "$VT_SCRIPT" "$@"
+                    fi
+                fi
+                APP_PATH="$TRY_PATH"
+                break
+            fi
+        done
+    fi
+    
+    # If not found in standard locations and VIBETUNNEL_PREFER_DERIVED_DATA wasn't set, search development builds
+    if [ -z "$APP_PATH" ] && [ -z "$VIBETUNNEL_PREFER_DERIVED_DATA" ]; then
+        # Try DerivedData (for development)
         for CANDIDATE in $(find ~/Library/Developer/Xcode/DerivedData -name "VibeTunnel.app" -type d 2>/dev/null | grep -v "\.dSYM" | grep -v "Index\.noindex"); do
             if [ -f "$CANDIDATE/Contents/Resources/vibetunnel" ]; then
                 VT_SCRIPT="$CANDIDATE/Contents/Resources/vt"
@@ -105,6 +124,23 @@ if [ -z "$VIBETUNNEL_BIN" ]; then
     fi
 fi
 
+# Log VibeTunnel binary info when VIBETUNNEL_PREFER_DERIVED_DATA is set
+if [ -n "$VIBETUNNEL_PREFER_DERIVED_DATA" ] && [ -n "$VIBETUNNEL_BIN" ]; then
+    # Get version and build info
+    VERSION_OUTPUT=$("$VIBETUNNEL_BIN" --version 2>&1)
+    VERSION_LINE=$(echo "$VERSION_OUTPUT" | grep "^VibeTunnel Server" | head -n 1)
+    BUILD_LINE=$(echo "$VERSION_OUTPUT" | grep "^Built:" | head -n 1)
+    
+    # Always log this info regardless of verbosity level
+    echo "[VibeTunnel] Using binary: $VIBETUNNEL_BIN"
+    if [ -n "$VERSION_LINE" ]; then
+        echo "[VibeTunnel] Version: ${VERSION_LINE#VibeTunnel Server }"
+    fi
+    if [ -n "$BUILD_LINE" ]; then
+        echo "[VibeTunnel] ${BUILD_LINE}"
+    fi
+fi
+
 # Check if we're already inside a VibeTunnel session
 if [ -n "$VIBETUNNEL_SESSION_ID" ]; then
     # Special case: handle 'vt title' command inside a session

web/src/server/api-socket-server.ts

@@ -23,6 +23,7 @@ import { createGitError } from './utils/git-error.js';
 import { areHooksInstalled, installGitHooks, uninstallGitHooks } from './utils/git-hooks.js';
 import { createLogger } from './utils/logger.js';
 import { prettifyPath } from './utils/path-prettify.js';
+import { BUILD_DATE, VERSION } from './version.js';
 import { createControlEvent } from './websocket/control-protocol.js';
 import { controlUnixHandler } from './websocket/control-unix-handler.js';
 
@@ -255,6 +256,8 @@ export class ApiSocketServer {
         running: true,
         port: this.serverPort,
         url: this.serverUrl,
+        version: VERSION,
+        buildDate: BUILD_DATE,
         followMode,
       };
 

web/src/server/pty/socket-protocol.ts

@@ -90,6 +90,8 @@ export interface StatusResponse {
   running: boolean;
   port?: number;
   url?: string;
+  version?: string;
+  buildDate?: string;
   followMode?: {
     enabled: boolean;
     branch?: string;