feat(sessions): add channelIdleMinutes config for per-channel session idle durations (#1353)

* feat(sessions): add channelIdleMinutes config for per-channel session idle durations

Add new `channelIdleMinutes` config option to allow different session idle
timeouts per channel. For example, Discord sessions can now be configured
to last 7 days (10080 minutes) while other channels use shorter defaults.

Config example:
  sessions:
    channelIdleMinutes:
      discord: 10080  # 7 days

The channel-specific idle is passed as idleMinutesOverride to the existing
resolveSessionResetPolicy, integrating cleanly with the new reset policy
architecture.

* fix

* feat: add per-channel session reset overrides (#1353) (thanks @cash-echo-bot)

---------

Co-authored-by: Cash Williams <cashwilliams@gmail.com>
Co-authored-by: Peter Steinberger <steipete@gmail.com>

src/commands/agent/session.ts

@@ -12,6 +12,7 @@ import {
   evaluateSessionFreshness,
   loadSessionStore,
   resolveAgentIdFromSessionKey,
+  resolveChannelResetConfig,
   resolveExplicitAgentSessionKey,
   resolveSessionResetPolicy,
   resolveSessionResetType,
@@ -99,7 +100,15 @@ export function resolveSession(opts: {
   const sessionEntry = sessionKey ? sessionStore[sessionKey] : undefined;
 
   const resetType = resolveSessionResetType({ sessionKey });
-  const resetPolicy = resolveSessionResetPolicy({ sessionCfg, resetType });
+  const channelReset = resolveChannelResetConfig({
+    sessionCfg,
+    channel: sessionEntry?.lastChannel ?? sessionEntry?.channel,
+  });
+  const resetPolicy = resolveSessionResetPolicy({
+    sessionCfg,
+    resetType,
+    resetOverride: channelReset,
+  });
   const fresh = sessionEntry
     ? evaluateSessionFreshness({ updatedAt: sessionEntry.updatedAt, now, policy: resetPolicy })
         .fresh