feat(docker): thread SessionDocker through Session + recovery

- Session: _docker field, constructor config, toState, createSessionOptions/
  respawnPaneOptions (both interactive + shell paths), docker getter
- resolveMuxAttachCwd returns /tmp for docker sessions (local wrapper only execs)
- skip the LOCAL claude version probe for docker; probe the IN-CONTAINER version
  instead (deferred) so wheel-forwarding stays enabled (#154)
- server restoreMuxSessions round-trips MuxSession.docker / SessionState.docker
- full CI suite green (3444 passed)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/session.ts

@@ -50,7 +50,9 @@ import {
   type EffortLevel,
   type GeminiConfig,
   type SessionRemote,
+  type SessionDocker,
 } from './types.js';
+import { probeDockerCliVersion } from './docker-hosts.js';
 import type { TerminalMultiplexer, MuxSession } from './mux-interface.js';
 import { TaskTracker, type BackgroundTask } from './task-tracker.js';
 import { RalphTracker } from './ralph-tracker.js';
@@ -178,6 +180,8 @@ export function isAltScreenStripMode(mode: SessionMode): boolean {
 const DEFAULT_PTY_COLS = 120;
 const DEFAULT_PTY_ROWS = 40;
 const TMUX_DISPLAY_TIMEOUT_MS = 2000;
+/** Delay before the in-container Claude CLI version probe (lets the container start). */
+const DOCKER_CLI_VERSION_PROBE_DELAY_MS = 3000;
 
 /**
  * Ask tmux for the current window geometry of `muxName` so a re-attaching PTY
@@ -212,8 +216,10 @@ export function queryTmuxWindowSize(muxName: string, socket: string): { cols: nu
   return { cols: DEFAULT_PTY_COLS, rows: DEFAULT_PTY_ROWS };
 }
 
-export function resolveMuxAttachCwd(workingDir: string, remote?: SessionRemote): string {
+export function resolveMuxAttachCwd(workingDir: string, remote?: SessionRemote, docker?: SessionDocker): string {
-  return remote ? '/tmp' : workingDir;
+  // Remote and docker sessions run the CLI elsewhere (ssh / docker exec); the LOCAL
+  // wrapper pane never needs the workspace as its cwd, so launch it in /tmp.
+  return remote || docker ? '/tmp' : workingDir;
 }
 
 /**
@@ -402,6 +408,10 @@ export class Session extends EventEmitter {
   // Remote execution metadata, present when this session runs over SSH through local tmux.
   private readonly _remote?: SessionRemote;
 
+  // Docker execution metadata, present when this session runs inside a container via
+  // local tmux + `docker exec`. The container is per-CASE (shared by sibling sessions).
+  private readonly _docker?: SessionDocker;
+
   // Session color for visual differentiation
   private _color: import('./types.js').SessionColor = 'default';
 
@@ -475,6 +485,8 @@ export class Session extends EventEmitter {
       attachmentHistory?: SessionAttachmentHistoryItem[];
       /** Remote execution metadata for sessions launched through SSH inside local tmux. */
       remote?: SessionRemote;
+      /** Docker execution metadata for sessions launched inside a container via local tmux. */
+      docker?: SessionDocker;
     }
   ) {
     super();
@@ -548,6 +560,7 @@ export class Session extends EventEmitter {
     }
     this._tmuxHistoryLimit = config.tmuxHistoryLimit ?? DEFAULT_TMUX_HISTORY_LIMIT;
     this._remote = config.remote;
+    this._docker = config.docker;
     if (config.attachmentHistory && config.attachmentHistory.length > 0) {
       this.restoreAttachmentHistory(config.attachmentHistory);
     }
@@ -649,6 +662,11 @@ export class Session extends EventEmitter {
     return this._claudeSessionId;
   }
 
+  /** Docker execution metadata when this session runs inside a container, else undefined. */
+  get docker(): SessionDocker | undefined {
+    return this._docker;
+  }
+
   // Adopt a Claude conversation ID observed from an external source (e.g. hook
   // payload). In interactive PTY mode Claude CLI emits no JSON to stdout, so
   // `_handleJsonMessage` never sees `session_id`; hooks are the only signal
@@ -1008,6 +1026,7 @@ export class Session extends EventEmitter {
       status: this._status,
       workingDir: this.workingDir,
       remote: this._remote,
+      docker: this._docker,
       currentTaskId: this._currentTaskId,
       createdAt: this.createdAt,
       lastActivityAt: this._lastActivityAt,
@@ -1197,7 +1216,7 @@ export class Session extends EventEmitter {
         name: 'xterm-256color',
         cols: ptyCols,
         rows: ptyRows,
-        cwd: resolveMuxAttachCwd(this.workingDir, this._remote),
+        cwd: resolveMuxAttachCwd(this.workingDir, this._remote, this._docker),
         // COD-75: codex/gemini get COLORTERM=truecolor — mirrors buildEnvExports()
         // in tmux-manager.ts so the attach client and the tmux session agree.
         env: buildMuxAttachEnv(this.mode === 'codex' || this.mode === 'gemini'),
@@ -1317,7 +1336,7 @@ export class Session extends EventEmitter {
     // repaint/alt-screen mode; issue #154). Remote sessions run claude on
     // another host, so a local probe wouldn't reflect their version — skip them
     // and let the banner scrape handle those. Cached process-wide, best-effort.
-    if (this.mode === 'claude' && !this._remote && !this._cliVersion) {
+    if (this.mode === 'claude' && !this._remote && !this._docker && !this._cliVersion) {
       const probedVersion = getClaudeCliVersion();
       if (probedVersion) {
         this._cliVersion = probedVersion;
@@ -1330,6 +1349,31 @@ export class Session extends EventEmitter {
       }
     }
 
+    // Docker sessions run claude INSIDE the container, so the local probe above
+    // reports the HOST claude (wrong version, and leaving cliVersion undefined
+    // silently disables wheel-forwarding, #154). Probe the IN-CONTAINER version
+    // instead — deferred so the container is up after the mux attach below.
+    if (this.mode === 'claude' && this._docker && !this._cliVersion) {
+      const dockerMeta = this._docker;
+      setTimeout(() => {
+        if (this._isStopped || this._cliVersion) return;
+        void probeDockerCliVersion(dockerMeta, this.mode)
+          .then((version) => {
+            if (!version || this._isStopped || this._cliVersion) return;
+            this._cliVersion = version;
+            this.emit('cliInfoUpdated', {
+              version: this._cliVersion,
+              model: this._cliModel,
+              accountType: this._cliAccountType,
+              latestVersion: this._cliLatestVersion,
+            });
+          })
+          .catch(() => {
+            /* best-effort */
+          });
+      }, DOCKER_CLI_VERSION_PROBE_DELAY_MS);
+    }
+
     // If mux wrapping is enabled, create or attach to a mux session
     if (this._useMux && this._mux) {
       try {
@@ -1350,6 +1394,7 @@ export class Session extends EventEmitter {
             effort: this._effort,
             historyLimit: this._tmuxHistoryLimit,
             remote: this._remote,
+            docker: this._docker,
           },
           createSessionOptions: {
             sessionId: this.id,
@@ -1368,6 +1413,7 @@ export class Session extends EventEmitter {
             effort: this._effort,
             historyLimit: this._tmuxHistoryLimit,
             remote: this._remote,
+            docker: this._docker,
           },
           spawnErrLabel: 'mux attachment',
         });
@@ -1738,6 +1784,7 @@ export class Session extends EventEmitter {
             envOverrides: this._envOverrides,
             historyLimit: this._tmuxHistoryLimit,
             remote: this._remote,
+            docker: this._docker,
           },
           createSessionOptions: {
             sessionId: this.id,
@@ -1748,6 +1795,7 @@ export class Session extends EventEmitter {
             envOverrides: this._envOverrides,
             historyLimit: this._tmuxHistoryLimit,
             remote: this._remote,
+            docker: this._docker,
           },
           spawnErrLabel: 'shell mux attachment',
         });

src/web/server.ts

@@ -2214,6 +2214,10 @@ export class WebServer extends EventEmitter {
               // erasing `remote` from state.json on the next persist. mux-sessions.json
               // round-trips MuxSession.remote; state.json carries SessionState.remote.
               remote: muxSession.remote ?? savedState?.remote,
+              // Docker metadata round-trips the same way (mux-sessions.json carries
+              // MuxSession.docker; state.json carries SessionState.docker), so recovery
+              // rebuilds the `docker exec` launch instead of a broken local command.
+              docker: muxSession.docker ?? savedState?.docker,
             });
 
             // Update session name if it was a "Restored:" placeholder or doesn't match saved name