docs(spec): humans/permissions granularity is V1, not OOS (#6744)

## Thinking Path

> - `doc/SPEC-implementation.md` §5.2 (Out of Scope V1) conflates two
distinct concerns into a single bullet: _"Multi-board governance or
role-based human permission granularity"_.
> - Role-based human permission granularity has been V1 for a while —
the `humans-and-permissions` plan and the `principal_permission_grants`
table shipped, the `PERMISSION_KEYS` set covers `users:invite`,
`users:manage_permissions`, `tasks:assign`, `tasks:assign_scope`,
`tasks:manage_active_checkouts`, `tasks:view_all`, `agents:view_all`,
`joins:approve`, `agents:create`, `environments:manage`.
> - The remaining OOS item from that bullet is _multi-board governance_
— running multiple board UIs against one company. That's a
deployment-topology concern, separate from permission granularity, and
stays V1 OOS.
> - This PR splits the bullet so the OOS list reflects reality and
contributors don't read the SPEC and conclude that per-user permission
scoping is unplanned.

## What Changed

Single-file docs edit in `doc/SPEC-implementation.md` §5.2:

- Drop the conflated "Multi-board governance or role-based human
permission granularity" bullet.
- Keep "Multi-board governance (multiple board UIs for a single
company)" as OOS — that part is still out of scope.
- Add a short paragraph below the OOS list pointing readers to the
`humans-and-permissions` plan, `principal_permission_grants`, and the
existing `tasks:view_all` + `agents:view_all` opt-out scoping primitives
so anyone reading §5.2 finds the V1 surface immediately.

## Verification

- N/A — docs-only change, no code/schema/test impact.

## Risks

- None. Single bullet rewording.

## Model Used

Claude (Anthropic). Model ID: `claude-opus-4-7`.

## Checklist

- [x] I have included a thinking path that traces from project context
to this change
- [x] I have specified the model used
- [x] I have checked ROADMAP.md and confirmed this PR does not duplicate
planned core work — it documents already-shipped V1 work that the SPEC
was lagging on
- [x] I have run tests locally and they pass — N/A docs-only
- [x] I have added or updated tests where applicable — N/A
- [x] If this change affects the UI, I have included before/after
screenshots — N/A docs-only
- [x] I have updated relevant documentation to reflect my changes — this
PR IS the doc update
- [x] I have considered and documented any risks above
- [x] I will address all Greptile and reviewer comments before
requesting merge

---------

Co-authored-by: Mike <ms@moar.tools>
Co-authored-by: Andrew Aymeloglu <aaymeloglu@gmail.com>

doc/SPEC-implementation.md

@@ -83,9 +83,13 @@ V1 implementation extends this baseline into a company-centric, governance-aware
 - Revenue/expense accounting beyond model/token costs
 - Knowledge base subsystem
 - Public marketplace (ClipHub)
-- Multi-board governance or role-based human permission granularity
+- Multi-board governance (multiple board UIs for a single company)
 - Automatic self-healing orchestration (auto-reassign/retry planners)
 
+Role-based human permission granularity is V1 — see the `humans-and-permissions`
+plan, the `principal_permission_grants` table, and the `PERMISSION_KEYS` set
+in `packages/shared/src/constants.ts`.
+
 ## 6. Architecture
 
 ## 6.1 Runtime Components