feat(fleet): add shared role semantics (#768)

packages/mosaic/framework/fleet/roles/LIBRARY.md

@@ -12,19 +12,22 @@ on demand. Engineering personas have no explicit `domain:` marker (they are the
 implicit `engineering` domain); cross-domain personas carry a `domain:` key in
 their intro so tooling can group them.
 
-> This file is an index only — no code imports it. To add a persona, drop a new
-> `*.md` next to the others (mirroring the existing structure) and add a row here.
+> This file is an index, not an authority source. The fleet persona resolver reads
+> its rows for discovery compatibility, then requires a readable `*.md` contract;
+> authority is derived from canonical class metadata in code, never from this prose.
 
 ## engineering
 
 | Persona         | Purpose                                                                        |
 | --------------- | ------------------------------------------------------------------------------ |
 | orchestrator    | Always-on coordinator — runs the supervisor loop, dispatches ready work        |
+| team-leader     | Coordinates only orchestrator-leased capacity for one bounded project          |
 | board           | Multi-lens deliberation panel; owns the mission's direction, not its execution |
 | planner         | Turns ratified objectives into a phased FR plan wired into a `depends_on` DAG  |
 | decomposition   | Splits FRs into one-PR-each cards wired with `depends_on` edges                |
 | code            | Primary executor — one card, one branch, one PR to green CI                    |
 | review          | Correctness reviewer — judges an open PR on correctness, scope, and coverage   |
+| validator       | Independent final evidence certificate; never approves-to-land or merges       |
 | security-review | Second line of review — secrets, auth, and forbidden-path safety               |
 | site-tester     | Runtime verifier — runs the change and checks behavior vs. acceptance criteria |
 | documentation   | Prose maintainer — keeps human-facing docs and projections in sync             |
@@ -33,6 +36,7 @@ their intro so tooling can group them.
 | operator        | Escalation and control surface — owns exceptions and the fleet pause switch    |
 | session-review  | Post-task retrospective — turns finished work into improvement signals         |
 | enhancer        | Continuous-improvement loop — upgrades the fleet's tools, skills, and harness  |
+| interaction     | Operator request/status surface; routes orchestration and merge decisions      |
 
 ## executive