v1.8.1: global agents + parser robustness + WS reconnect toast

Builtins move out of code into /data/AGENTS.md (always-on, mounted ro
into the container); per-project AGENTS.md is now an optional override.
agents.ts merges global + project entries with project-wins-by-name and
caches per-source mtimes (60s TTL). Parser switches to per-block
try/catch and returns AgentsResponse { agents, errors[] } so one
malformed block no longer fails the file. AgentPicker shows a
non-blocking amber chip listing skipped blocks and only fires a gray
toast when zero agents loaded.

WS reconnect UX (useUserEvents + useSessionStream) now silent on the
first disconnect; createWsReconnectToast escalates to gray after 3
failures or 15 s, then to red with a Retry Now action after 60 s.
useSessionStream also gained the exponential-backoff reconnect it was
missing.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/web/src/api/types.ts

@@ -30,7 +30,10 @@ export interface Session {
   agent_id: string | null;
 }
 
-export type AgentSource = 'builtin' | 'file';
+// v1.8.1: 'global' = /data/AGENTS.md (always-on), 'project' = per-project
+// override at <root>/AGENTS.md. In-code builtins were retired; the seed file
+// lives at /data/AGENTS.md.
+export type AgentSource = 'global' | 'project';
 
 export interface Agent {
   id: string;
@@ -43,9 +46,14 @@ export interface Agent {
   source: AgentSource;
 }
 
+export interface AgentParseError {
+  agent_name: string;
+  reason: string;
+}
+
 export interface AgentsResponse {
   agents: Agent[];
-  parse_error: string | null;
+  errors: AgentParseError[];
 }
 
 export const CHAT_STATUSES = ['open', 'archived'] as const;