fix: 5 critical/high-priority bugs (auth bypass, relay failures, unbounded recursion, context growth) (#1083)

* fix: address 5 critical and high-priority bugs from issue tracker

- #1033: reject webhook requests when secret is cleared at runtime via
  update_secret(None), preventing auth bypass through SIGHUP hot-swap
- #908: reset consecutive_failures counter on successful SSE stream
  reconnection in relay channel, so circuit breaker counts truly
  consecutive failures
- #975: add depth limit (16) to validate_tool_schema() to prevent
  stack overflow on deeply nested schemas
- #974: add depth limit (8) to resolve_nested() to prevent stack
  overflow on deeply nested capabilities wrappers
- #826: truncate oversized tool outputs (>8KB) in routine lightweight
  loop to prevent unbounded context growth across iterations

Each fix includes a regression test.

Closes #1033, #908, #975, #974, #826

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix: 5 more high-priority bugs (routine cache, job signals, input limits)

- #1077: recompute next_fire_at when re-enabling cron routines via web
  toggle, mirroring CLI behavior so cron ticker picks them up
- #1076: refresh event trigger cache after web toggle/delete operations
  so event/system_event routines reflect changes immediately
- #892: remove Stuck from check_signals() stop-states in JobDelegate
  since Stuck is recoverable (Stuck -> InProgress via self-repair)
- #976: truncate oversized description strings in CapabilitiesFile to
  4KB to prevent memory abuse from malicious capabilities files
- #977: drop oversized parameters schema JSON (>64KB) in
  CapabilitiesFile to prevent unbounded memory growth

Each fix includes regression tests where applicable.

Closes #1077, #1076, #892, #976, #977

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* fix: prevent ReDoS in event trigger regex patterns

- #825: use RegexBuilder with 64KB size limit when compiling
  user-supplied event trigger patterns, both at creation time
  (routine tool) and at cache refresh (routine engine)

Note: Rust's regex crate already guarantees O(n) matching, so the
size limit prevents excessive memory use during compilation rather
than catastrophic backtracking at match time.

Closes #825

Co-Authored-By: Claude Opus 4.6 <[email protected]>

* Harden HTTP SSRF IP filtering

* Apply rustfmt after staging merge

---------

Co-authored-by: Claude Opus 4.6 <[email protected]>

src/channels/web/handlers/routines.rs

@@ -190,12 +190,21 @@ pub async fn routines_toggle_handler(
         None => !routine.enabled,
     };
 
+    // When re-enabling a cron routine, recompute next_fire_at so the cron
+    // ticker can pick it up. Mirrors the CLI behavior (issue #1077).
     if routine.enabled
         && !was_enabled
-        && let Trigger::Cron { schedule, timezone } = &routine.trigger
+        && let Trigger::Cron {
+            ref schedule,
+            ref timezone,
+        } = routine.trigger
     {
-        routine.next_fire_at = next_cron_fire(schedule, timezone.as_deref())
-            .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;
+        routine.next_fire_at = next_cron_fire(schedule, timezone.as_deref()).map_err(|e| {
+            (
+                StatusCode::INTERNAL_SERVER_ERROR,
+                format!("Failed to compute next fire: {e}"),
+            )
+        })?;
     }
 
     store
@@ -203,6 +212,12 @@ pub async fn routines_toggle_handler(
         .await
         .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;
 
+    // Refresh the in-memory event trigger cache so event/system_event
+    // routines reflect the new enabled state immediately (issue #1076).
+    if let Some(engine) = state.routine_engine.read().await.as_ref() {
+        engine.refresh_event_cache().await;
+    }
+
     Ok(Json(serde_json::json!({
         "status": if routine.enabled { "enabled" } else { "disabled" },
         "routine_id": routine_id,
@@ -227,6 +242,12 @@ pub async fn routines_delete_handler(
         .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;
 
     if deleted {
+        // Refresh the in-memory event trigger cache so deleted event/system_event
+        // routines stop firing immediately (issue #1076).
+        if let Some(engine) = state.routine_engine.read().await.as_ref() {
+            engine.refresh_event_cache().await;
+        }
+
         Ok(Json(serde_json::json!({
             "status": "deleted",
             "routine_id": routine_id,