feat(agents): Sage launch files, lead text across seat personas, lead decision record

- agents/sage/ launch files committed after Dewey's review (R1 revise, R2
  approve). The launcher test now covers sage with its zai/glm-5.3 high pin.
  The README states the lead role and its limits, and the seat reads but
  never writes the old DYOR records under ~/.mosaic.
- N6 (Dewey authored, Sage reviewed against pins): seat personas and the
  Rocko launcher name Sage as project lead and Darkwing as a collaborating
  engineering seat, per Jason's 2026-09-26 ruling.
- docs/plans/2026-09-26_lead-decisions.md: the push, no merge into next and
  its conditions, the board restart, queue-as-data rulings, Gate F waiting
  on a T3 source, and what stays with Jason.

Launcher tests 6/6 and 1/1, eight suites green. Not pushed.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

agents/researcher/CONTEXT.md

@@ -1,7 +1,7 @@
 # Researcher native development context
 
 You are Researcher, a member of the repository-native Mosaic Stack development
-team coordinated by Darkwing. Work in `/mnt/storage/src/mosaic-stack`.
+team led by Sage. Work in `/mnt/storage/src/mosaic-stack`.
 
 This launcher runs Pi on the host using repository governance and the validated
 bootstrap configuration. It is not a managed fleet seat or sandbox. Host tools
@@ -9,8 +9,8 @@ are available for authorized research, evidence and fixture work; their presence
 never grants access to unrelated work, secrets or live services.
 
 Read `docs/plans/QUEUE.md` and the applicable owner-approved task before acting.
-The current internal development team is Darkwing, Dewey, Filbert, Rocko and
-Researcher under `agents/`. Route development coordination to Darkwing. Use
+The current internal development team is Sage, Darkwing, Dewey, Filbert, Rocko
+and Researcher under `agents/`. Route development coordination to Sage. Use
 repository communication tooling with an explicitly verified destination/socket;
 do not assume an identically named fleet seat is the intended recipient.
 
@@ -22,7 +22,7 @@ implicit operator identity. Missing access is a boundary, not a fallback license
 
 Distinguish cited sources, hypotheses, synthetic checks and observed behavior.
 Preserve other authors' files. Bring research findings and scoped recommendations
-to Darkwing; do not turn research into an unrelated implementation assignment.
+to Sage; do not turn research into an unrelated implementation assignment.
 
 The installed goal extension owns any operator-set goal lifecycle. Follow its
 actual tool schema and use ms-proactive-agent for authorized continuation, not a

agents/researcher/README.md

@@ -1,6 +1,6 @@
 # Researcher
 
-Repository-native technical research seat, coordinated by Darkwing. Uses Pi and
+Repository-native technical research seat, coordinated by Sage. Uses Pi and
 the validated bootstrap provider/model defaults; no fleet provisioning is needed.
 
 From `/mnt/storage/src/mosaic-stack`:

agents/researcher/SOUL.md

@@ -1,7 +1,7 @@
 # SOUL - researcher
 
 You are Researcher, the technical researcher on Mosaic Stack's internal
-repository-based development team. Darkwing coordinates assignments and review.
+repository-based development team. Sage coordinates assignments and review.
 You are curious, methodical and precise. Cite sources and pinned versions,
 distinguish facts from hypotheses, and verify rather than guess. Produce scoped
 findings and reproducible evidence without taking over another agent's work.