Fix spurious container snapshot on every start for projects with env vars

Migrate env-var-based checks in container_needs_recreation() to label-based
checks. When a container snapshot is committed, Docker merges the image's env
vars with the container's, causing get_env() to return stale values and
triggering an infinite snapshot→recreate loop. Labels are immutable after
creation and immune to this merging behavior.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/src-tauri/src/docker/container.rs

@@ -704,6 +704,13 @@ pub async fn create_container(
     labels.insert("triple-c.timezone".to_string(), timezone.unwrap_or("").to_string());
     labels.insert("triple-c.mcp-fingerprint".to_string(), compute_mcp_fingerprint(mcp_servers));
     labels.insert("triple-c.mission-control".to_string(), project.mission_control_enabled.to_string());
+    labels.insert("triple-c.custom-env-fingerprint".to_string(), custom_env_fingerprint.clone());
+    labels.insert("triple-c.instructions-fingerprint".to_string(),
+        combined_instructions.as_ref().map(|s| sha256_hex(s)).unwrap_or_default());
+    labels.insert("triple-c.git-user-name".to_string(), project.git_user_name.clone().unwrap_or_default());
+    labels.insert("triple-c.git-user-email".to_string(), project.git_user_email.clone().unwrap_or_default());
+    labels.insert("triple-c.git-token-hash".to_string(),
+        project.git_token.as_ref().map(|t| sha256_hex(t)).unwrap_or_default());
 
     let host_config = HostConfig {
         mounts: Some(mounts),
@@ -1000,41 +1007,32 @@ pub async fn container_needs_recreation(
         return Ok(true);
     }
 
-    // ── Git environment variables ────────────────────────────────────────
-    let env_vars = info
-        .config
-        .as_ref()
-        .and_then(|c| c.env.as_ref());
-
-    let get_env = |name: &str| -> Option<String> {
-        env_vars.and_then(|vars| {
-            vars.iter()
-                .find(|v| v.starts_with(&format!("{}=", name)))
-                .map(|v| v[name.len() + 1..].to_string())
-        })
-    };
-
-    let container_git_name = get_env("GIT_USER_NAME");
-    let container_git_email = get_env("GIT_USER_EMAIL");
-    let container_git_token = get_env("GIT_TOKEN");
-
-    if container_git_name.as_deref() != project.git_user_name.as_deref() {
-        log::info!("GIT_USER_NAME mismatch (container={:?}, project={:?})", container_git_name, project.git_user_name);
+    // ── Git settings (label-based to avoid stale snapshot env vars) ─────
+    let expected_git_name = project.git_user_name.clone().unwrap_or_default();
+    let container_git_name = get_label("triple-c.git-user-name").unwrap_or_default();
+    if container_git_name != expected_git_name {
+        log::info!("GIT_USER_NAME mismatch (container={:?}, project={:?})", container_git_name, expected_git_name);
         return Ok(true);
     }
-    if container_git_email.as_deref() != project.git_user_email.as_deref() {
-        log::info!("GIT_USER_EMAIL mismatch (container={:?}, project={:?})", container_git_email, project.git_user_email);
+
+    let expected_git_email = project.git_user_email.clone().unwrap_or_default();
+    let container_git_email = get_label("triple-c.git-user-email").unwrap_or_default();
+    if container_git_email != expected_git_email {
+        log::info!("GIT_USER_EMAIL mismatch (container={:?}, project={:?})", container_git_email, expected_git_email);
         return Ok(true);
     }
-    if container_git_token.as_deref() != project.git_token.as_deref() {
+
+    let expected_git_token_hash = project.git_token.as_ref().map(|t| sha256_hex(t)).unwrap_or_default();
+    let container_git_token_hash = get_label("triple-c.git-token-hash").unwrap_or_default();
+    if container_git_token_hash != expected_git_token_hash {
         log::info!("GIT_TOKEN mismatch");
         return Ok(true);
     }
 
-    // ── Custom environment variables ──────────────────────────────────────
+    // ── Custom environment variables (label-based fingerprint) ──────────
     let merged_env = merge_custom_env_vars(global_custom_env_vars, &project.custom_env_vars);
     let expected_fingerprint = compute_env_fingerprint(&merged_env);
-    let container_fingerprint = get_env("TRIPLE_C_CUSTOM_ENV").unwrap_or_default();
+    let container_fingerprint = get_label("triple-c.custom-env-fingerprint").unwrap_or_default();
     if container_fingerprint != expected_fingerprint {
         log::info!("Custom env vars mismatch (container={:?}, expected={:?})", container_fingerprint, expected_fingerprint);
         return Ok(true);
@@ -1048,15 +1046,16 @@ pub async fn container_needs_recreation(
         return Ok(true);
     }
 
-    // ── Claude instructions ───────────────────────────────────────────────
+    // ── Claude instructions (label-based fingerprint) ─────────────────────
     let expected_instructions = build_claude_instructions(
         global_claude_instructions,
         project.claude_instructions.as_deref(),
         &project.port_mappings,
         project.mission_control_enabled,
     );
-    let container_instructions = get_env("CLAUDE_INSTRUCTIONS");
-    if container_instructions.as_deref() != expected_instructions.as_deref() {
+    let expected_instructions_fp = expected_instructions.as_ref().map(|s| sha256_hex(s)).unwrap_or_default();
+    let container_instructions_fp = get_label("triple-c.instructions-fingerprint").unwrap_or_default();
+    if container_instructions_fp != expected_instructions_fp {
         log::info!("CLAUDE_INSTRUCTIONS mismatch");
         return Ok(true);
     }

app/src/components/terminal/TerminalView.tsx

@@ -35,6 +35,12 @@ export default function TerminalView({ sessionId, active }: Props) {
   const [detectedUrl, setDetectedUrl] = useState<string | null>(null);
   const [imagePasteMsg, setImagePasteMsg] = useState<string | null>(null);
   const [isAtBottom, setIsAtBottom] = useState(true);
+  const [isAutoFollow, setIsAutoFollow] = useState(true);
+  const isAtBottomRef = useRef(true);
+  // Tracks user intent to follow output — only set to false by explicit user
+  // actions (mouse wheel up), not by xterm scroll events during writes.
+  const autoFollowRef = useRef(true);
+  const lastUserScrollTimeRef = useRef(0);
 
   useEffect(() => {
     if (!containerRef.current) return;
@@ -131,10 +137,40 @@ export default function TerminalView({ sessionId, active }: Props) {
       sendInput(sessionId, data);
     });
 
-    // Track scroll position to show "Jump to Current" button
+    // Detect user-initiated scroll-up (mouse wheel) to pause auto-follow.
+    // Captured during capture phase so it fires before xterm's own handler.
+    const handleWheel = (e: WheelEvent) => {
+      lastUserScrollTimeRef.current = Date.now();
+      if (e.deltaY < 0) {
+        autoFollowRef.current = false;
+        setIsAutoFollow(false);
+        isAtBottomRef.current = false;
+        setIsAtBottom(false);
+      }
+    };
+    containerRef.current.addEventListener("wheel", handleWheel, { capture: true, passive: true });
+
+    // Track scroll position to show "Jump to Current" button.
+    // Debounce state updates via rAF to avoid excessive re-renders during rapid output.
+    let scrollStateRafId: number | null = null;
     const scrollDisposable = term.onScroll(() => {
       const buf = term.buffer.active;
-      setIsAtBottom(buf.viewportY >= buf.baseY);
+      const atBottom = buf.viewportY >= buf.baseY;
+      isAtBottomRef.current = atBottom;
+
+      // Re-enable auto-follow only when USER scrolls to bottom (not write-triggered)
+      const isUserScroll = (Date.now() - lastUserScrollTimeRef.current) < 300;
+      if (atBottom && isUserScroll && !autoFollowRef.current) {
+        autoFollowRef.current = true;
+        setIsAutoFollow(true);
+      }
+
+      if (scrollStateRafId === null) {
+        scrollStateRafId = requestAnimationFrame(() => {
+          scrollStateRafId = null;
+          setIsAtBottom(isAtBottomRef.current);
+        });
+      }
     });
 
     // Track text selection to show copy hint in status bar
@@ -187,7 +223,15 @@ export default function TerminalView({ sessionId, active }: Props) {
 
     const outputPromise = onOutput(sessionId, (data) => {
       if (aborted) return;
-      term.write(data);
+      term.write(data, () => {
+        if (autoFollowRef.current) {
+          term.scrollToBottom();
+          if (!isAtBottomRef.current) {
+            isAtBottomRef.current = true;
+            setIsAtBottom(true);
+          }
+        }
+      });
       detector.feed(data);
 
       // Scan for SSO refresh marker in terminal output
@@ -231,6 +275,9 @@ export default function TerminalView({ sessionId, active }: Props) {
         if (!containerRef.current || containerRef.current.offsetWidth === 0) return;
         fitAddon.fit();
         resize(sessionId, term.cols, term.rows);
+        if (autoFollowRef.current) {
+          term.scrollToBottom();
+        }
       });
     });
     resizeObserver.observe(containerRef.current);
@@ -246,9 +293,11 @@ export default function TerminalView({ sessionId, active }: Props) {
       scrollDisposable.dispose();
       selectionDisposable.dispose();
       setTerminalHasSelection(false);
+      containerRef.current?.removeEventListener("wheel", handleWheel, { capture: true });
       containerRef.current?.removeEventListener("paste", handlePaste, { capture: true });
       outputPromise.then((fn) => fn?.());
       exitPromise.then((fn) => fn?.());
+      if (scrollStateRafId !== null) cancelAnimationFrame(scrollStateRafId);
       if (resizeRafId !== null) cancelAnimationFrame(resizeRafId);
       resizeObserver.disconnect();
       try { webglRef.current?.dispose(); } catch { /* may already be disposed */ }
@@ -280,6 +329,9 @@ export default function TerminalView({ sessionId, active }: Props) {
         }
       }
       fitRef.current?.fit();
+      if (autoFollowRef.current) {
+        term.scrollToBottom();
+      }
       term.focus();
     } else {
       // Release WebGL context for inactive terminals
@@ -314,8 +366,30 @@ export default function TerminalView({ sessionId, active }: Props) {
   }, [detectedUrl]);
 
   const handleScrollToBottom = useCallback(() => {
-    termRef.current?.scrollToBottom();
-    setIsAtBottom(true);
+    const term = termRef.current;
+    if (term) {
+      autoFollowRef.current = true;
+      setIsAutoFollow(true);
+      fitRef.current?.fit();
+      term.scrollToBottom();
+      isAtBottomRef.current = true;
+      setIsAtBottom(true);
+    }
+  }, []);
+
+  const handleToggleAutoFollow = useCallback(() => {
+    const next = !autoFollowRef.current;
+    autoFollowRef.current = next;
+    setIsAutoFollow(next);
+    if (next) {
+      const term = termRef.current;
+      if (term) {
+        fitRef.current?.fit();
+        term.scrollToBottom();
+        isAtBottomRef.current = true;
+        setIsAtBottom(true);
+      }
+    }
   }, []);
 
   return (
@@ -338,6 +412,19 @@ export default function TerminalView({ sessionId, active }: Props) {
           {imagePasteMsg}
         </div>
       )}
+      {/* Auto-follow toggle - top right */}
+      <button
+        onClick={handleToggleAutoFollow}
+        className={`absolute top-2 right-4 z-50 px-2 py-1 rounded text-[10px] font-medium border shadow-sm transition-colors cursor-pointer ${
+          isAutoFollow
+            ? "bg-[#1a2332] text-[#3fb950] border-[#238636] hover:bg-[#1f2d3d]"
+            : "bg-[#1f2937] text-[#8b949e] border-[#30363d] hover:bg-[#2d3748]"
+        }`}
+        title={isAutoFollow ? "Auto-scrolling to latest output (click to pause)" : "Auto-scroll paused (click to resume)"}
+      >
+        {isAutoFollow ? "▼ Following" : "▽ Paused"}
+      </button>
+      {/* Jump to Current - bottom right, when scrolled up */}
       {!isAtBottom && (
         <button
           onClick={handleScrollToBottom}