fix(webui): address #905 REQUEST_CHANGES on notifications classifier

B1: classify_attention_event uses structured flags/category only — never
substring-match human-authored title/summary for escalation.

B2: make notification ids unique across probe_errors and collisions
(include loop index / kind).

B3: do not assign probe_errors to fetch_error (avoids false Fetch Warning
and double-reporting).

Regression tests cover all three blockers.

Refs #648

webui/notifications.py

@@ -7,13 +7,12 @@ operators receive direct alerts only for human-required escalation boundaries
 
 from __future__ import annotations
 
-import os
 from dataclasses import dataclass, field
 from datetime import datetime, timezone
-from typing import Any, Callable, Sequence
+from typing import Any, Callable
 
 from webui import console_redaction
-from webui.project_registry import find_project, load_registry
+from webui.project_registry import load_registry
 from webui.queue_loader import QueueSnapshot, load_queue_snapshot
 from webui.lease_loader import LeaseSnapshot, load_lease_snapshot
 from webui.system_health import SystemHealthSnapshot, load_system_health
@@ -158,7 +157,13 @@ def classify_attention_event(
     2. Operational queues (blocker, stale lease, unassigned ready work, queue collision)
        -> ATTENTION_OPERATOR (requires_human=False).
     3. Routine state transitions (clean progression, healthy heartbeats) -> ATTENTION_ROUTINE (requires_human=False).
+
+    Classification uses structured flags and category only. Human-authored
+    ``title`` / ``summary`` text is never substring-matched for escalation
+    (PR #905 review B1) — callers that need text signals must set flags from
+    machine-generated status/detail fields before calling this function.
     """
+    del title, summary  # kept for API stability; never used for classification
     if (
         is_hard_stop
         or is_auth_failure
@@ -166,9 +171,6 @@ def classify_attention_event(
         or is_decision_lock
         or is_validation_failure
         or category in {CATEGORY_AUTH, CATEGORY_VALIDATION}
-        or "hard stop" in summary.lower()
-        or "unauthorized" in summary.lower()
-        or "irrecoverable" in summary.lower()
     ):
         return ATTENTION_HUMAN_REQUIRED, True
 
@@ -234,7 +236,7 @@ def load_notifications_snapshot(
     now_iso = datetime.now(timezone.utc).isoformat()
 
     # 1. System health alerts (highest priority)
-    for probe_err in getattr(health_snap, "probe_errors", ()):
+    for err_idx, probe_err in enumerate(getattr(health_snap, "probe_errors", ())):
         att_cls, req_human = classify_attention_event(
             CATEGORY_SYSTEM,
             "System Health Probe Error",
@@ -243,7 +245,7 @@ def load_notifications_snapshot(
         )
         items.append(
             NotificationItem(
-                id=f"notif-sys-err-{project.id}",
+                id=f"notif-sys-err-{project.id}-{err_idx}",
                 attention_class=att_cls,
                 category=CATEGORY_SYSTEM,
                 title="System Health Error",
@@ -431,16 +433,18 @@ def load_notifications_snapshot(
                 )
             )
 
-    for collision in lease_snap.duplicate_prs:
+    for col_idx, collision in enumerate(lease_snap.duplicate_prs):
         att_cls, req_human = classify_attention_event(
             CATEGORY_BLOCKER,
             f"Duplicate PR Collision ({collision.kind})",
             collision.message,
             is_blocker=True,
         )
+        issue_part = collision.issue_number if collision.issue_number is not None else "none"
+        kind_part = (collision.kind or "unknown").replace(" ", "-")
         items.append(
             NotificationItem(
-                id=f"notif-collision-{collision.issue_number or 0}",
+                id=f"notif-collision-{kind_part}-{issue_part}-{col_idx}",
                 attention_class=att_cls,
                 category=CATEGORY_BLOCKER,
                 title=f"Collision Alert ({collision.kind})",
@@ -459,7 +463,9 @@ def load_notifications_snapshot(
     operator_count = sum(1 for i in items if i.attention_class == ATTENTION_OPERATOR)
     routine_count = sum(1 for i in items if i.attention_class == ATTENTION_ROUTINE)
 
-    fetch_err = queue_snap.fetch_error or lease_snap.fetch_error or getattr(health_snap, "probe_errors", None)
+    # Fetch errors are transport/load failures only — not probe results that
+    # already surface as first-class notification items (PR #905 review B3).
+    fetch_err = queue_snap.fetch_error or lease_snap.fetch_error
     if isinstance(fetch_err, (tuple, list)):
         fetch_err = "; ".join(fetch_err) if fetch_err else None