feat: workspaceHooksEnabled setting as the opt-out for workspace hook installs

Installing hooks into any workspace a Claude session runs in is the right
default, but it takes a decision away from a user who deliberately removed
them: nothing on disk distinguishes "removed on purpose" from "never had any",
so they would come back on the next session create.

Adds the synced workspaceHooksEnabled setting (App Settings -> Agents & CLIs ->
Claude), default ON. OFF restores the older behavior exactly: a Codeman hooks
block that is already present is still refreshed when stale (COD-91), but one
is never added.

Every create path routes through one applyWorkspaceHooks() helper so the gate
cannot apply to some paths only, and the boot-time recovery sweep honours it too.

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

src/web/schemas.ts

@@ -906,6 +906,17 @@ export const SettingsUpdateSchema = z
      * add-only at create; a marker keeps user-authored copies untouched.
      */
     agentSkillEnabled: z.boolean().optional(),
+    /**
+     * Install Codeman's hooks block into the workspace of every Claude session,
+     * not only into cases Codeman scaffolded itself. SYNCED, default ON: without
+     * it a linked case or an existing repo runs with no hooks at all, and each
+     * hook-driven surface is silently dead there (tab alert, Approvals Inbox,
+     * push, respawn's definitive idle signals, the wait endpoints' stop/blocked).
+     * Turning it OFF restores the older, narrower behavior — a Codeman hooks
+     * block that is already present is still refreshed when stale, but one is
+     * never added — for a user who wants Codeman to leave their repos alone.
+     */
+    workspaceHooksEnabled: z.boolean().optional(),
     /**
      * Let browser dictation transcribe through this machine's Claude Code login,
      * the same speech-to-text service the CLI's own `/voice` mode uses