feat: add unknown-rendition baseline planning for Terminal 1.18

[uniblab]

Summary

• Add TerminalScreenPlanner.PlanRenditionBaseline() for safe recovery from unknown physical rendition state.
• Preserve opaque, same-session planning/transaction ownership and all stable 1.x behavior.
• Freeze the identical net8.0 / net9.0 / net10.0 public API and qualify the stable 1.18.0 package.
• Synchronize the main/version roadmaps, release notes, README, architecture, compatibility, security, package metadata, and API baseline.

Contract

The new operation derives obligations from selected-profile attribute-entry and color-selection evidence before reversible normalization. It restores every exposed rendition axis or returns null:

• prefer a global attribute reset;
• otherwise emit every required safe specific exit in stable underline, standout, italic, strikeout order;
• restore original colors after attribute restoration;
• allow a zero-byte plan only when no enterable attribute or selectable color axis is exposed.

Existing PlanRenditionTransition(...), PlanRenditionReset(current), normalization, operation-plan opacity, output epochs, cancellation, serialization, and cleanup semantics are unchanged. No TermInfo type, capability identifier, terminal string, or expansion API enters the public surface.

Qualification

• Final head: 8fc4a0a194f365285615b9fb475eca60fca7e30a
• Final exact-head workflow: 35384014876 — all nine jobs green
• Stable-package evidence workflow: 35382158657
• Unit tests: 2,383 passed per target framework
• TermInfo integration tests: 15 passed per target framework
• Public API SHA-256: 48975f2c42f6c544e9c574a9b3d79f7e2b7b3ecb10ab1a5a0b7067749e38e65d
• Icod.Terminal.1.18.0.nupkg SHA-256: e8f2b374fd0865aa151910686197096b344f7daf8d0ef72331520d944b322932
• Icod.Terminal.1.18.0.snupkg SHA-256: 8a14d163f2ea0bf030bea0416e0a84a919a2e8c83c692956b3a2a98470d78422
• Published Icod.DCurses 1.6.0 soak and TermInfo-free future-renderer package consumer passed on all target frameworks.
• Independent final review: spec compliance PASS, code quality PASS, no Critical, Important, or Minor findings.
• Inline review threads: none.

Dependency boundary and follow-up

Production dependencies remain Icod.TermInfo 1.15.0 and Icod.Timing 1.0.0. The retained DCurses PR #32 exact-byte witness resumes only after this package is published, per its published-package criterion.

This PR remains draft for maintainer handoff. No merge, tag, GitHub Release, or NuGet publication is included.

[uniblab]

T180 RED checkpoint:

• Established the unpublished 1.18.0-alpha.1 identity.
• Added the focused unit witness and TermInfo-free future-DCurses compile binding for TerminalScreenPlanner.PlanRenditionBaseline().
• Exact head: 53dadc26d69e20b8e681dc3cb940fa0e84b5373b.
• Pull-request run: 35377018637.
• Representative Linux job: 105703974194.
• RED result: the same expected CS1061 for the absent PlanRenditionBaseline() API on net8.0, net9.0, and net10.0; no production implementation is present at this checkpoint.

Proceeding to T181 minimal implementation.

[uniblab]

T184 negative API-baseline gate proof

The deliberate mismatch behavior is recorded by pull-request run 35379264781, package-candidate job 105711285369.

That job successfully built the package project and generated byte-identical public API snapshots for net8.0, net9.0, and net10.0, then intentionally failed the frozen-baseline gate because:

• selected baseline: docs/Public-API-Baseline-1.17.sha256
• expected fingerprint: c0a051a925d551e526343ef59d8c47d75e41868d84235fa30bfa7debe1b3ceb9
• generated 1.18 fingerprint: 48975f2c42f6c544e9c574a9b3d79f7e2b7b3ecb10ab1a5a0b7067749e38e65d

The verifier rejected the mismatch at VerifyPublicApiBaseline.ps1:70 before package artifact publication. After review of the additive signature, the active selector was moved to the frozen 1.18 fingerprint. Exact-head run 35380187310 then passed the package-candidate, all package shards, API/XML, downstream DCurses, and validated-artifact gates.

This records both sides of T184 Step 6: a deliberate mismatch fails, and the reviewed 1.18 baseline succeeds.

[uniblab]

Icod.Terminal 1.18.0 stable-candidate closure

T180-T185 are complete.

• Final PR head: 8fc4a0a194f365285615b9fb475eca60fca7e30a
• Final exact-head workflow: run 35384014876 — all nine jobs green
• Recorded stable-package qualification: run 35382158657
• Unit tests: 2,383 passed per target framework
• TermInfo integration tests: 15 passed per target framework
• Public API SHA-256: 48975f2c42f6c544e9c574a9b3d79f7e2b7b3ecb10ab1a5a0b7067749e38e65d
• Icod.Terminal.1.18.0.nupkg SHA-256: e8f2b374fd0865aa151910686197096b344f7daf8d0ef72331520d944b322932
• Icod.Terminal.1.18.0.snupkg SHA-256: 8a14d163f2ea0bf030bea0416e0a84a919a2e8c83c692956b3a2a98470d78422
• Published DCurses 1.6.0 soak and the TermInfo-free future-renderer package witness passed on net8.0/net9.0/net10.0.
• Independent final review: spec compliance PASS, code quality PASS, no Critical, Important, or Minor findings.

The stable gate caught and drove correction of stale 1.17.1 NuGet release-note metadata and packed-README release/install wording before acceptance. The final authority-label cleanup is documentation-only.

The retained DCurses PR #32 witness remains deferred until Icod.Terminal 1.18.0 is actually published, per its published-package criterion. No merge, tag, GitHub Release, or NuGet publication was performed.