feat(docker): take run-mode availability from the container

The run-mode dropdown hides CLIs that are not installed on the HOST (#201). That
is right for local sessions and wrong for a container case, whose agents run
inside the container: a host with no claude installed hides the mode while the
container ships one, which is exactly what happened on a real deployment.

The adoption preflight already probes what the container has, so that result is
persisted on the case and surfaced through CaseInfo. Docker cases gate on it;
every other case keeps the host probe unchanged.

An absent list reads as "do not gate" rather than "nothing available": an owned
container runs our base image, which ships every CLI, and treating unknown as
empty would leave the menu with Shell alone.

src/types/api.ts

@@ -167,6 +167,13 @@ export interface CaseInfo {
     image?: string;
     path: string;
     network?: string;
+    /**
+     * CLIs available INSIDE the container. A container case runs its agents in
+     * the container, so HOST CLI availability says nothing about what it can
+     * run. Absent = unknown (an owned container runs our base image, which ships
+     * every CLI), which the UI reads as "do not gate".
+     */
+    availableModes?: string[];
   };
 }
 

src/types/session.ts

@@ -261,6 +261,15 @@ export interface DockerCase {
    * all created by us).
    */
   owned?: boolean;
+  /**
+   * CLIs found INSIDE the container by the adoption preflight. A container case
+   * runs its agents in the container, so host CLI availability says nothing about
+   * what this case can run — the base image ships every CLI, and an adopted
+   * container ships whatever its owner installed. Absent = unknown (owned cases,
+   * or a case linked before this field existed), which callers read as "do not
+   * gate".
+   */
+  availableModes?: SessionMode[];
   /** Last captured Claude conversation id, replayed via --resume on a fresh launch. */
   lastClaudeSessionId?: string;
 }

src/web/public/session-ui.js

@@ -474,9 +474,23 @@ Object.assign(CodemanApp.prototype, {
    * run modes like the rest, and neither `agy` nor `pi` is likely to be installed.
    */
   _refreshRunModeAvailability(menu) {
+    // A DOCKER case runs its agents INSIDE the container, so host CLI
+    // availability answers the wrong question: the host may have no claude at
+    // all while the container ships one, and gating on the host hides a mode
+    // that would have worked. Adoption records what the container really has
+    // (`availableModes`); an owned container runs our base image, which ships
+    // every CLI, so an absent list means "do not gate" rather than "nothing".
+    // Same source every run* path reads the selected case from.
+    const caseName = document.getElementById('quickStartCase')?.value;
+    const activeCase = caseName ? (this.cases || []).find((c) => c.name === caseName) : null;
+    const containerModes = activeCase?.location === 'docker' ? activeCase.docker?.availableModes : null;
     for (const mode of ['claude', 'opencode', 'codex', 'gemini', 'antigravity', 'pi', 'grok', 'deepseek']) {
       const btn = menu.querySelector(`.run-mode-option[data-mode="${mode}"]`);
-      if (btn) btn.style.display = this.isCliAvailable(mode) ? 'flex' : 'none';
+      if (!btn) continue;
+      let available;
+      if (activeCase?.location === 'docker') available = containerModes ? containerModes.includes(mode) : true;
+      else available = this.isCliAvailable(mode);
+      btn.style.display = available ? 'flex' : 'none';
     }
     // DeepSeek is the one mode whose availability has two halves: `dsh` can be
     // perfectly installed while no pane-capable profile exists, because DeepSeek

src/web/routes/case-routes.ts

@@ -297,6 +297,7 @@ export function registerCaseRoutes(app: FastifyInstance, ctx: EventPort & Config
           image: host.image,
           path: dockerCase.hostWorkspacePath,
           network: host.network ?? 'bridge',
+          ...(dockerCase.availableModes ? { availableModes: dockerCase.availableModes } : {}),
         },
       };
       const existingIndex = cases.findIndex((item) => item.name === dockerCase.name);
@@ -851,15 +852,19 @@ export function registerCaseRoutes(app: FastifyInstance, ctx: EventPort & Config
         return createErrorResponse(ApiErrorCode.OPERATION_FAILED, probe.error || 'container is not adoptable');
       }
 
-      await writeDockerCases(CODEMAN_CONFIG_DIR, [...dockerCases, dockerCase]);
+      // Persist what the container actually has: the run-mode picker gates on
+      // HOST CLIs, which is the wrong question for a case whose agents run inside
+      // a container the host knows nothing about.
+      const adoptedCase = { ...dockerCase, availableModes: probe.availableModes };
+      await writeDockerCases(CODEMAN_CONFIG_DIR, [...dockerCases, adoptedCase]);
       ctx.broadcast(SseEvent.CaseLinked, {
-        name: dockerCase.name,
+        name: adoptedCase.name,
-        path: dockerCase.hostWorkspacePath,
+        path: adoptedCase.hostWorkspacePath,
         type: 'docker',
       });
       return {
         success: true,
-        data: { case: dockerCase, image: probe.image, availableModes: probe.availableModes },
+        data: { case: adoptedCase, image: probe.image, availableModes: probe.availableModes },
       };
     }
   );

test/docker-adopted-container.test.ts

@@ -194,6 +194,34 @@ describe('adopted container: the Add Case panel id contract', () => {
   });
 });
 
+describe('adopted container: run modes come from the CONTAINER, not the host', () => {
+  const ui = readFileSync(new URL('../src/web/public/session-ui.js', import.meta.url), 'utf8');
+  /** Slice the method BODY. Anchored on the definition, not a call site: the
+   *  menu opener calls _loadRunModeHistory() ABOVE this definition, so slicing
+   *  between call sites silently yields an empty string and passes nothing. */
+  const refreshFn = (src) => {
+    const start = src.indexOf('_refreshRunModeAvailability(menu) {');
+    expect(start).toBeGreaterThan(-1);
+    return src.slice(start, start + 1600);
+  };
+
+  it('gates a docker case on availableModes instead of host CLI probes', () => {
+    // The sandbox host had codex but no claude while the adopted container had
+    // claude and no codex; gating on the host hid the only mode that worked.
+    const fn = refreshFn(ui);
+    expect(fn).toContain("location === 'docker'");
+    expect(fn).toContain('availableModes');
+    // Non-docker cases must keep the original host probe (#201).
+    expect(fn).toContain('this.isCliAvailable(mode)');
+  });
+
+  it('leaves an owned container ungated when nothing was probed', () => {
+    // Our base image ships every CLI, so an absent list means "unknown", and
+    // treating unknown as "nothing available" would empty the menu.
+    expect(refreshFn(ui)).toMatch(/containerModes \?[^:]*:\s*true/);
+  });
+});
+
 describe('adopted container: drift is not evaluated', () => {
   it('reports no drift rather than demanding a recreate we may not perform', async () => {
     // An adopted container carries no codeman.confighash label, so a real