0.10.0-S07: Distribution hardening: signing decision, update channel, SmartScreen exit

[mberrys]

Session 0.10.0-S07 · type surface · milestone 0.10.0 — Platform Hardening, Extension Ecosystem & 1.0 Readiness

GA preparation. All graduated-automation stages hardened.

Delivers

Distribution hardening: signing decision executed, update channel, SmartScreen exit or documented re-deferral.

Scope and ownership boundary

• This session owns: One adapter (CLI, PageMaster) over typed contracts.
• This session may not: Semantics divergence.
• The milestone must not create: new product-scope features hiding as "hardening", a web shell, or a second language runtime.
• Out of scope for the milestone: New capability families; anything that widens authority boundaries.

Tasks

• Execute the installer-signing procurement decision, or re-defer it explicitly by recorded decision.
• Define and implement the update channel policy.
• Achieve the SmartScreen exit, or document the re-deferral and its operator-facing consequence.
• Maintain checksum continuity across the change.
• Test the update policy end to end.
• Produce the session handoff packet (exact SHA, changed files, tests run, deviations, remaining risks) — the only valid inter-session interface.

Dependencies

• 0.10.0-S00 — 0.10.0-S00: Reconcile base SHA, public-contract inventory, and deferred decisions #467

Runs as an independent lane alongside S05/S08.

Parallel lanes

Sanctioned parallelism for 0.10.0: S02/S03 after S01; S05/S07/S08 as independent lanes; S09 after S03 and S07.

Lanes run concurrently only where the session map marks them; concurrency outside the sanctioned lanes is not permitted.

Exit evidence

Signed-or-decided evidence recorded; update policy tested.

PR titles, commit messages, and document headlines are never acceptance evidence. Only this session's exit evidence, on an exact SHA, closes this gate.

Milestone context

Objective. Declare and freeze the 1.0 public contract surface (CLI envelopes, persisted schema kinds, plugin capability ABI, documented behaviour) with a deprecation policy; ship the versioned plugin SDK with admission policy and threat review; run the performance/scale program on named benchmark identities; harden distribution (signing procurement decision, update channel, SmartScreen exit); decide macOS explicitly; refresh the security/privacy audit; complete operator documentation; and assemble the 1.0 readiness dossier with release-candidate criteria demonstrated on an exact SHA.

Stop rules. A contract that cannot be fixture-frozen is redesigned or labelled experimental - never silently promised. Scale/performance failures block the release candidate; missing platform evidence is unavailable, not PASS.

Authoring note

Per the rolling-wave rule in section 7 of the roadmap, the fully executable specification for this session (exact starting SHA, allowed layers and files, components to reuse, named tests, escalation conditions) is authored when the milestone activates, after its S00 reconcile. This issue carries the fixed frame — objective, boundary, dependencies, and exit evidence — and is refined, not replaced, at activation.

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Full context: docs/ROADMAP_0.5.0-0.10.0.md section 4.6 and docs/github-milestones/0.10.0.md.