fix(agent): bound push suppression to observed browser attention

docs/api/streaming-chat.md

@@ -377,7 +377,9 @@ Attached input admission and its request binding are atomic. Replay verifies the
 
 ### Agent attention and shared read events (push v1)
 
-Web auth frames add `{ "clientKind":"web", "presenceSessionId":"per-document-uuid" }` to the existing `type`, `token`, and optional `after`. Report the same UUID to `PUT /v1/agent/presence/:sessionId` across the entire authenticated workspace. Native iOS clients add `clientKind:"native"`; no browser-attention lease is required for a native app. These declarations classify a client under the existing shared principal and do not grant new authority. Old/unclassified authenticated sockets conservatively veto push delivery until closed/expired. A web-classified socket without a live matching presence receipt is also unknown. Transport ping/pong renews connection liveness, never user activity. The proxy classifies itself upstream using the authenticated `X-Sybil-Client: backend-proxy-v1` upgrade header.
+Web auth frames always add `clientKind:"web"` to the existing `type`, `token`, and optional `after`. They also add `presenceSessionId:"per-document-uuid"` when secure UUID creation succeeds; omit only that field if unavailable. Report the same UUID to `PUT /v1/agent/presence/:sessionId` across the entire authenticated workspace. Native iOS clients add `clientKind:"native"`; no browser-attention lease is required for a native app. These declarations classify a client under the existing shared principal and do not grant new authority. Explicit document visibility/focus/interaction receipts, bound to that credential generation and session, determine attention independently of sockets. Every fresh visible/focused session suppresses, even while idle; hidden/blur transitions and recent visible interaction have 5-second grace, and unrenewed explicit observations expire after 60 seconds.
+
+Old/unclassified authenticated sockets and web sockets with no matching observation share one persisted 5-second introduction grace per credential generation. Reconnects, missing/new UUIDs and transport heartbeat cannot extend or restart it. A spent anonymous window does not weaken any genuine document lease; an expired observed lease does not become unknown merely because its socket remains connected. Ping/pong updates only existing connection liveness, preserving the original kind/session and never recreating a removed row as unknown. The proxy classifies itself upstream using the authenticated `X-Sybil-Client: backend-proxy-v1` upgrade header.
 
 The backend adds this optional server-to-client frame after a successful monotonic read advance, including a runtime-native browser acknowledgment merged into the shared row:
 
@@ -389,4 +391,4 @@ The backend adds this optional server-to-client frame after a successful monoton
 
 Distinguish an unbound room from one already bound to a legacy absent/null source or a source UUID. Bind on the first accepted read state; if history arrives first, pin the legacy state before publishing it. A different source in a later GET, stream frame or PUT acknowledgment, including null-to-UUID or UUID-to-null, must stop stale read writes and require an explicit fresh room load. Preserve the old snapshot and cursors until that reload, then fetch read state before fresh history; never attach a new UUID to an old cursor. Ordinary foreground/network recovery must not reset this stopped room. HTTP 409, an invalid acknowledgment cursor or an acknowledgment below the requested cursor also stops the writer. A transient transport failure can retry only within the same pinned source. None of these client reloads resets server read state.
 
-Older clients may ignore unknown server frame types. `read_state` and presence are not client subscribe messages and are never forwarded to runtime as generic frames. Push consent, revoke, presence, retry/expiry and notification payload contracts live in [rest.md](./rest.md#agent-push-notifications-v1). The runtime built-in browser has its own authenticated presence/read inputs; its unknown sessions participate in the same conservative veto. No Web Push is used for invisible read synchronization.
+Older clients may ignore unknown server frame types. `read_state` and presence are not client subscribe messages and are never forwarded to runtime as generic frames. Push consent, revoke, presence, retry/expiry and notification payload contracts live in [rest.md](./rest.md#agent-push-notifications-v1). The runtime built-in browser has its own authenticated presence/read inputs and bounded anonymous grace per runtime source. The separate 60-second restart safety intervals and source/clock uncertainty checks remain in effect. No Web Push is used for invisible read synchronization.