fix: store token lock identity at acquire time for Slack and Discord

Community review (devoruncommented) correctly identified that the Slack
adapter re-read SLACK_APP_TOKEN from os.getenv() during disconnect,
which could differ from the value used during connect if the environment
changed. Discord had the same pattern with self.config.token (less risky
but still not bulletproof).

Both now follow the Telegram pattern: store the token identity on self
at acquire time, use the stored value for release, clear after release.

Also fixes docs: alias naming was hermes-<name> in docs but actual
implementation creates <name> directly (e.g. ~/.local/bin/coder not
~/.local/bin/hermes-coder).

gateway/platforms/slack.py

@@ -95,6 +95,7 @@ class SlackAdapter(BasePlatformAdapter):
         try:
             # Acquire scoped lock to prevent duplicate app token usage
             from gateway.status import acquire_scoped_lock
+            self._token_lock_identity = app_token
             acquired, existing = acquire_scoped_lock('slack-app-token', app_token, metadata={'platform': 'slack'})
             if not acquired:
                 owner_pid = existing.get('pid') if isinstance(existing, dict) else None
@@ -149,12 +150,12 @@ class SlackAdapter(BasePlatformAdapter):
                 logger.warning("[Slack] Error while closing Socket Mode handler: %s", e, exc_info=True)
         self._running = False
 
-        # Release the token lock
+        # Release the token lock (use stored identity, not re-read env)
         try:
             from gateway.status import release_scoped_lock
-            app_token = os.getenv("SLACK_APP_TOKEN")
-            if app_token:
-                release_scoped_lock('slack-app-token', app_token)
+            if getattr(self, '_token_lock_identity', None):
+                release_scoped_lock('slack-app-token', self._token_lock_identity)
+                self._token_lock_identity = None
         except Exception:
             pass