feat(deepseek): add DeepSeek Harness (dsh) as a ninth CLI run mode

Adds `mode: 'deepseek'` alongside claude/shell/opencode/codex/gemini/
antigravity/pi/grok, plus a shortcut that opens the harness's own browser UI
as a Codeman web tab.

DeepSeek is wired unlike its siblings in three ways, each of which is the
reason for a design decision rather than an accident:

1. The agent is a PROFILE, not the binary. `dsh` is a launcher over
   $DSH_HOME/profiles/<name>, and DeepSeek ships only `web`, `headless` and
   `base` -- the interactive terminal front door is always a third-party
   plugin. So availability is two questions: `isDeepSeekAvailable()` (binary)
   and `isDeepSeekRunnable()` (binary AND a pane-capable profile). The Run
   button gates on the latter, because reporting only the binary would spawn a
   pane that dies on arrival. When the binary is present but no profile is,
   the run menu offers to install one (POST /api/deepseek/install-profile).

2. The permission switch is an env var, not a flag. The harness has no
   command-line permission option; its sandbox/approval rows read
   DSH_PERMISSION_MODE (read-only / workspace-write / danger-full-access).
   Exported via `tmux setenv`, never on the spawn line. Absent = the harness's
   own workspace-write, which still asks, so the multi-user clamp is the
   only-if-sent branch and clamps to workspace-write, never read-only.

3. It is the only non-claude mode that passes hooksAvailableForMode(), and it
   earned that. The terminal front door reports idle/working/blocked to a
   supervising process over a generic env-gated contract; a generated shim
   (deepseek-status-shim.ts) makes Codeman that supervisor and forwards each
   report to /api/hook-event as stop / agent_working / permission_prompt. So a
   dsh session gets definitive respawn triggers, real wait-endpoint signals and
   real Approvals Inbox items instead of output-stabilization guesswork.
   `agent_working` is new (157th SSE constant) and joins
   APPROVAL_RESOLVING_EVENTS so a dialog answered in the terminal clears its
   alert at once.

The resolver needs the strictest identity probe of the family: `dsh` is not
merely a squattable npm name, Debian ships an unrelated `dsh` (dancer's shell),
so `dsh --help` must print the harness's own banner before a candidate is
handed a spawn line.

Model is deliberately not a session field -- it is a composition entry in the
profile's config tree. Env allowlist gains DSH_* and DEEPSEEK_* only; provider
keys named by a settings-file `apiKeyEnv` stay out, which is pi's
34-provider-key problem in a new shape.

Verified live against dsh 0.1.1-rc.2 and @deepseek-harness-tui/dsh-tui: the
status endpoint's two-part answer, the no-profile refusal, the profile
bootstrap, a real session whose pane runs `dsh --profile dsh-tui` with the
permission mode injected via setenv, and the full status bridge -- a
send-and-wait returned signal "stop" from a real turn, and blocked/working
created and cleared an Approvals Inbox item.

Docs: docs/deepseek-integration.md (guide), docs/deepseek-integration-plan.md
(decisions + honest gaps). Tests: test/deepseek-mode.test.ts,
test/deepseek-cli-resolver.test.ts.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/types/session.ts

@@ -8,7 +8,7 @@
  * - SessionConfig — creation-time config (id, workingDir, createdAt)
  * - SessionOutput — captured stdout/stderr/exitCode
  * - SessionStatus — 'idle' | 'busy' | 'stopped' | 'error'
- * - SessionMode — 'claude' | 'shell' | 'opencode' | 'codex' | 'gemini' | 'antigravity' | 'pi' | 'grok' (which CLI backend)
+ * - SessionMode — 'claude' | 'shell' | 'opencode' | 'codex' | 'gemini' | 'antigravity' | 'pi' | 'grok' | 'deepseek' (which CLI backend)
  * - ClaudeMode — CLI permission mode ('dangerously-skip-permissions' | 'auto' | 'normal' | 'allowedTools')
  * - SessionColor — visual differentiation color
  * - OpenCodeConfig — OpenCode-specific settings (model, autoAllowTools, continueSession)
@@ -17,6 +17,7 @@
  * - AntigravityConfig — Antigravity CLI (agy) settings (model, dangerouslySkipPermissions, resumeConversationId)
  * - PiConfig — Pi CLI (pi.dev) settings (model, provider, thinking, resume/continue, project trust)
  * - GrokConfig — Grok Build CLI (xAI `grok`) settings (model, alwaysApprove, resume/continue)
+ * - DeepSeekConfig — DeepSeek Harness (`dsh`) settings (profile, permissionMode, resume, status bridge)
  *
  * Cross-domain relationships:
  * - SessionState.respawnConfig embeds RespawnConfig (respawn domain)
@@ -45,11 +46,20 @@ export type SessionStatus = 'idle' | 'busy' | 'stopped' | 'error';
 export type ClaudeMode = 'dangerously-skip-permissions' | 'auto' | 'normal' | 'allowedTools';
 
 /** Session mode: which CLI backend a session runs */
-export type SessionMode = 'claude' | 'shell' | 'opencode' | 'codex' | 'gemini' | 'antigravity' | 'pi' | 'grok';
+export type SessionMode =
+  | 'claude'
+  | 'shell'
+  | 'opencode'
+  | 'codex'
+  | 'gemini'
+  | 'antigravity'
+  | 'pi'
+  | 'grok'
+  | 'deepseek';
 
 export type RemoteCommandMode = Extract<
   SessionMode,
-  'shell' | 'claude' | 'opencode' | 'codex' | 'gemini' | 'antigravity' | 'pi' | 'grok'
+  'shell' | 'claude' | 'opencode' | 'codex' | 'gemini' | 'antigravity' | 'pi' | 'grok' | 'deepseek'
 >;
 
 /**
@@ -158,7 +168,7 @@ export interface RemoteSessionInfo {
 /** Which CLI backends a Docker case can run (same set as remote). */
 export type DockerCommandMode = Extract<
   SessionMode,
-  'shell' | 'claude' | 'opencode' | 'codex' | 'gemini' | 'antigravity' | 'pi' | 'grok'
+  'shell' | 'claude' | 'opencode' | 'codex' | 'gemini' | 'antigravity' | 'pi' | 'grok' | 'deepseek'
 >;
 
 /** Container engine. Docker and Podman differ in the uid/userns + host-gateway alias. */
@@ -388,6 +398,61 @@ export interface GrokConfig {
   resumeSessionId?: string;
 }
 
+/**
+ * DeepSeek Harness (`dsh`) session configuration.
+ *
+ * Two things make this config shaped unlike every sibling above it.
+ *
+ * **1. The agent is a PROFILE, not the binary.** `dsh` is a launcher: it boots
+ * `$DSH_HOME/profiles/<name>`, an ordered stack of plugin-bundle patch layers.
+ * DeepSeek ships only `web`, `headless` and `base`, so the interactive terminal
+ * agent is always a third-party profile the user installed. `profile` is
+ * therefore the primary knob, and an absent one resolves to the first
+ * pane-capable profile found (see resolveDefaultDeepSeekProfile).
+ *
+ * **2. Permissions are an ENV VAR, not a flag.** The harness has no
+ * `--dangerously-skip-permissions` equivalent; its sandbox and approval rows are
+ * config, driven by one documented input, `DSH_PERMISSION_MODE`, with three
+ * presets (measured from `dsh --dump-default-config`):
+ *
+ *   read-only          sandbox read-only,          approval ask
+ *   workspace-write    sandbox workspace-write,    approval ask     <- default
+ *   danger-full-access sandbox danger-full-access, approval never
+ *
+ * This is the one place a Codeman env export is the RIGHT mechanism rather than
+ * the forbidden one: unlike `CLAUDE_CODE_EFFORT_LEVEL` (which hard-locks
+ * in-session `/effort`), `DSH_PERMISSION_MODE` is read with `??` as a boot-time
+ * DEFAULT, so it stays a soft default the user can still change in-session. It
+ * is exported via `tmux setenv`, never on the spawn command line.
+ */
+export interface DeepSeekConfig {
+  /**
+   * Profile under `$DSH_HOME/profiles` to boot (`dsh --profile <name>`). Absent
+   * = the first pane-capable profile installed. A `web`/`headless` profile is
+   * refused at spawn time: neither can drive an interactive pane.
+   */
+  profile?: string;
+  /**
+   * Sandbox + approval preset, exported as `DSH_PERMISSION_MODE`. Absent = the
+   * harness's own `workspace-write` default, which still ASKS — which is why the
+   * multi-user clamp only needs the only-if-sent branch here, like
+   * codex/antigravity/grok rather than pi.
+   */
+  permissionMode?: 'read-only' | 'workspace-write' | 'danger-full-access';
+  /** Resume the most recent session for this workspace (`--resume`). */
+  resumeSession?: boolean;
+  /** Resume a specific session by ID (`--resume <id>`). Wins over resumeSession. */
+  resumeSessionId?: string;
+  /**
+   * Report idle/working/blocked back to Codeman through the Herdr-compatible
+   * status shim (see `deepseek-status-shim.ts`). Default ON: it upgrades this
+   * mode from output-stabilization guessing to definitive hook events. Only
+   * TUIs that implement the contract report; for one that does not, this is
+   * inert rather than harmful.
+   */
+  statusReporting?: boolean;
+}
+
 /**
  * Configuration for creating a new session
  */
@@ -553,6 +618,8 @@ export interface SessionState {
   piConfig?: PiConfig;
   /** Grok-specific configuration (only for mode === 'grok') */
   grokConfig?: GrokConfig;
+  /** DeepSeek Harness configuration (only for mode === 'deepseek') */
+  deepSeekConfig?: DeepSeekConfig;
   /** Claude conversation session ID to resume after reboot (set by restore script) */
   resumeSessionId?: string;
   /** Claude CLI effort level (soft default via --settings, switchable in-session via /effort) */