policy: enter roadmap construction mode

[yihanzhu]

Closes #187

Outcome

Enter a temporary ystack-self construction mode so the agreed Roadmap can be implemented directly as machine-gated PRs. This does not enable real-target use or operating mode.

• Roadmap implementation skips repeated intake/G1/G2/plan and human merge gates.
• Every change still requires a PR, required CI, independent exact-head/base review, tests, and a coherent inactive repository state.
• The current operator-authorized Codex construction session may publish exact passing PRs. No shipped yshifu/publisher capability is claimed.
• Real targets, credentials, release/install/profile activation, deployment, production actions, and irreversible external writes remain disabled.
• Every pre-mode attempt is stale unless a fresh post-transition brief explicitly adopts it. Frozen Add the v1 portable core contract validator (inactive) #183 and the portable-core plan remain preserved.
• The first real development use requires an operator-merged operating-mode transition.

Trust and bootstrap

The mode record binds the repository, activation base, operator-authorized source Roadmap/north-star blobs, effective post-transition blobs, frozen #183 tuple, restore-manifest trust floor, and exact desired post-transition ruleset.

The operator directly authorized this one bootstrap in the active session. This PR still requires exact CI and independent review. No other PR inherits the bootstrap. After merge, the construction session will reconcile ruleset 21500323 to PR + strict required ci + zero approvals + no bypass actors before any Roadmap unit.

Proof

• pinned ShellCheck 0.11.0: clean on tracked scripts plus the new runner
• generic test runner: all 8 scripts passed
• north-star resolver: 74 passed
• north-star gate/consumer: 226 passed
• models parser: 63 passed
• degraded-review tests: 105 passed
• v2 pending/round/quota/rename suites: passed
• structure manifest, JSON, shell syntax, rename gate, and git diff check: passed
• two independent exact-blob reviews: PASS

This transition is intentionally auto-merged after GitHub CI and final independent Codex review. It does not wait for a human merge.

[yihanzhu]

Codex reviewer (cross-vendor, read-only)

Reviewed-head: 7510c6c
Reviewed-base: 7a55da7
reviewer: operator-default @ high

Posted verbatim by codex-review.sh (codex exec review --json --base refs/codex-review/188-43864/base in an isolated temp worktree, sandbox forced read-only). Comments only — Codex never pushes, approves, or merges.

The construction-mode identities match the changed Roadmap and north-star blobs, and the consolidated test runner preserves coverage of all existing test scripts. No actionable regression was identified.