Discord: thread bindings idle + max-age lifecycle (#27845) (thanks @osolmaz)

* refactor discord thread bindings to idle and max-age lifecycle

* fix: migrate legacy thread binding expiry and reduce hot-path disk writes

* refactor: remove remaining thread-binding ttl legacy paths

* fix: harden thread-binding lifecycle persistence

* Discord: fix thread binding types in message/reply paths

* Infra: handle win32 unknown inode in file identity checks

* Infra: relax win32 guarded-open identity checks

* Config: migrate threadBindings ttlHours to idleHours

* Revert "Infra: relax win32 guarded-open identity checks"

This reverts commit de94126771.

* Revert "Infra: handle win32 unknown inode in file identity checks"

This reverts commit 96fc5ddfb3.

* Discord: re-read live binding state before sweep unbind

* fix: add changelog note for thread binding lifecycle update (#27845) (thanks @osolmaz)

---------

Co-authored-by: Onur Solmaz <onur@textcortex.com>

docs/tools/subagents.md

@@ -30,7 +30,8 @@ These commands work on channels that support persistent thread bindings. See **T
 - `/focus <subagent-label|session-key|session-id|session-label>`
 - `/unfocus`
 - `/agents`
-- `/session ttl <duration|off>`
+- `/session idle <duration|off>`
+- `/session max-age <duration|off>`
 
 `/subagents info` shows run metadata (status, timestamps, session id, transcript path, cleanup).
 
@@ -95,14 +96,14 @@ When thread bindings are enabled for a channel, a sub-agent can stay bound to a
 
 ### Thread supporting channels
 
-- Discord (currently the only supported channel): supports persistent thread-bound subagent sessions (`sessions_spawn` with `thread: true`), manual thread controls (`/focus`, `/unfocus`, `/agents`, `/session ttl`), and adapter keys `channels.discord.threadBindings.enabled`, `channels.discord.threadBindings.ttlHours`, and `channels.discord.threadBindings.spawnSubagentSessions`.
+- Discord (currently the only supported channel): supports persistent thread-bound subagent sessions (`sessions_spawn` with `thread: true`), manual thread controls (`/focus`, `/unfocus`, `/agents`, `/session idle`, `/session max-age`), and adapter keys `channels.discord.threadBindings.enabled`, `channels.discord.threadBindings.idleHours`, `channels.discord.threadBindings.maxAgeHours`, and `channels.discord.threadBindings.spawnSubagentSessions`.
 
 Quick flow:
 
 1. Spawn with `sessions_spawn` using `thread: true` (and optionally `mode: "session"`).
 2. OpenClaw creates or binds a thread to that session target in the active channel.
 3. Replies and follow-up messages in that thread route to the bound session.
-4. Use `/session ttl` to inspect/update auto-unfocus TTL.
+4. Use `/session idle` to inspect/update inactivity auto-unfocus and `/session max-age` to control the hard cap.
 5. Use `/unfocus` to detach manually.
 
 Manual controls:
@@ -110,11 +111,11 @@ Manual controls:
 - `/focus <target>` binds the current thread (or creates one) to a sub-agent/session target.
 - `/unfocus` removes the binding for the current bound thread.
 - `/agents` lists active runs and binding state (`thread:<id>` or `unbound`).
-- `/session ttl` only works for focused bound threads.
+- `/session idle` and `/session max-age` only work for focused bound threads.
 
 Config switches:
 
-- Global default: `session.threadBindings.enabled`, `session.threadBindings.ttlHours`
+- Global default: `session.threadBindings.enabled`, `session.threadBindings.idleHours`, `session.threadBindings.maxAgeHours`
 - Channel override and spawn auto-bind keys are adapter-specific. See **Thread supporting channels** above.
 
 See [Configuration Reference](/gateway/configuration-reference) and [Slash commands](/tools/slash-commands) for current adapter details.