fix(ui): stream phase progress without gates

docs/contracts/workflow-observable-baseline.md

@@ -24,6 +24,7 @@ The gate suite fixes:
 - F3 rewritten question and assumptions, including mutation failure ordering;
 - F4 Evidence used, accepted, rejected, and legacy-without-corpus projections;
 - F8 Memory promotion accepted, declined, and absent, including mutation failure ordering;
+- a newly folded phase is announced once in RPC mode even when it requires no human gate;
 - resume reconstruction for the touched F1, F2, F3, F4, and F8 states;
 - artifact payload compatibility, anti-bypass behavior, and final phase closing.
 
@@ -73,6 +74,7 @@ These suites fix:
 - new-session versus resume Pi prompts;
 - refusal to resume finalized, archived, foreign, unavailable, or read-only sessions;
 - Pi RPC to client event mapping, SSE replay/reset behavior, and runtime replacement ordering;
+- reserved Pi phase notifications mapped to sanitized `phase_started` client events;
 - failure persistence and sanitization before a client-visible response.
 
 ### Frontend client
@@ -92,6 +94,7 @@ These suites fix:
 
 - widget registry and gate response payloads;
 - `ui_request`, `text_delta`, activity, usage, and lifecycle event reduction;
+- phase progress and the active workflow dot advancing on `phase_started` without a `ui_request`;
 - stream replacement, cursor reset, reconnection, and pending-text flush behavior;
 - session document projections shown to the reviewer.