fix(ralph-loop): clear orphaned state when original session no longer exists (#446)

* fix(ralph-loop): clear orphaned state when original session no longer exists

When a session with an active ralph-loop terminates abnormally (abort, window close),
the state file remains with active: true. Previously, when a new session started,
the hook would skip the orphaned state without cleaning it up.

This fix adds session existence validation:
- Before skipping a loop owned by a different session, check if that session still exists
- If the original session no longer exists, clear the orphan state and log
- If the original session still exists, skip as before (it's another active session's loop)

Changes:
- Add checkSessionExists option to RalphLoopOptions for dependency injection
- Wire up sessionExists from session-manager as the default implementation
- Add tests for orphan state cleanup and active session preservation

* fix(ralph-loop): add error handling around checkSessionExists call

Wraps the async checkSessionExists call in try/catch for consistency
with other async operations in this file. If the check throws, logs
the error and falls back to the original behavior (not clearing state).

---------

Co-authored-by: sisyphus-dev-ai <sisyphus-dev-ai@users.noreply.github.com>

src/hooks/ralph-loop/index.ts

@@ -64,6 +64,7 @@ export function createRalphLoopHook(
   const stateDir = config?.state_dir
   const getTranscriptPath = options?.getTranscriptPath ?? getDefaultTranscriptPath
   const apiTimeout = options?.apiTimeout ?? DEFAULT_API_TIMEOUT
+  const checkSessionExists = options?.checkSessionExists
 
   function getSessionState(sessionID: string): SessionState {
     let state = sessions.get(sessionID)
@@ -199,6 +200,24 @@ export function createRalphLoopHook(
       }
 
       if (state.session_id && state.session_id !== sessionID) {
+        if (checkSessionExists) {
+          try {
+            const originalSessionExists = await checkSessionExists(state.session_id)
+            if (!originalSessionExists) {
+              clearState(ctx.directory, stateDir)
+              log(`[${HOOK_NAME}] Cleared orphaned state from deleted session`, {
+                orphanedSessionId: state.session_id,
+                currentSessionId: sessionID,
+              })
+              return
+            }
+          } catch (err) {
+            log(`[${HOOK_NAME}] Failed to check session existence`, {
+              sessionId: state.session_id,
+              error: String(err),
+            })
+          }
+        }
         return
       }