spec: retarget the four remaining "v11" datings of the #3290 session-alias removal to v16 (.describe() strings + migration rationale) #10079

Split out of #9872 (its delivering PR #9990 fixed the 20 comment-text sites; these four sit on spec runtime-data surfaces the ruling there forbade touching). Provenance: os-dev report on #9872, 2026-08-19; residue re-verified on origin/main b1457eeca at triage time 2026-08-20.

The #3290 removal of the ctx.session.tenantId alias shipped in v16 (the only release page citing #3290 is content/docs/releases/v16.mdx; its 16.0.0 upgrade checklist carries the rename step). Four spec-package sites still date it "v11":

• packages/spec/src/ui/action-params.zod.ts:376 — .describe() string: "on the v11 session-alias removal path (Unify the developer-facing org identifier: hooks expose session.tenantId while RLS/seed/columns use organizationId (add organizationId as the blessed name) #3280 deprecate → Remove the deprecated hook/action ctx.session.tenantId alias in the next major (converge on organizationId) #3290 remove …)"
• packages/spec/src/ui/action-params.zod.ts:409 — .describe() string: "removal follows the v11 session-alias removal path"
• packages/spec/src/migrations/registry.ts:1555 — migration rationale prose: "the v11 session-alias removal already walked (Unify the developer-facing org identifier: hooks expose session.tenantId while RLS/seed/columns use organizationId (add organizationId as the blessed name) #3280 deprecated → Remove the deprecated hook/action ctx.session.tenantId alias in the next major (converge on organizationId) #3290 removed)"
• packages/spec/src/migrations/entries/semantic/17.action-session-roles-to-positions.ts:23 — same sentence

Notes for the dispatching seat (spec lane):

• The .describe() strings are runtime data that regenerate content/docs/references/ui/action-params.mdx (marked AUTO-GENERATED — regenerate with the repo tooling, never hand-edit) and flow into spec-changes.json / docs/protocol-upgrade-guide.md:317. Regenerate wholesale, don't patch outputs.
• Text-only provenance correction: no schema shape, acceptance, or public-surface change is in scope — expected Clause-②: no. If implementation finds otherwise, stop and report a fork.
• Do NOT sweep other "v11" tokens: two sites date different removals to v11 correctly (content/docs/kernel/contracts/metadata-service.mdx:311, docs/audits/2026-07-security-props-liveness-recheck.md:26), objectui#3290 is a different repo's issue, and CHANGELOG entries are historical records — all verified out-of-population under [finding] ~10 comments date the #3290 session.tenantId removal to "v11", but it shipped in v16 — and there is no v11 release page at all #9872.
• content/docs/releases/** stays untouched (release notes are already correct and are never edited in a code PR).