spec(port): port specs/port/trios-railway/crates/trios-railway-experience/src/lib.t27 (Closes #9769)

[dmitrii-f-t27]

Summary

Port gHashTag/trios-railway:crates/trios-railway-experience/src/lib.rs (at 8b229e9489ee, 140+ lines) as specs/port/trios-railway/crates/trios-railway-experience/src/lib.t27 — Roadmap Stage 6 (goal #4548), target t27c gen-rust. Closes #9769.

The original is the append-only writer for .trinity/experience/<YYYYMMDD>.trinity, enforcing L7 (the experience log) and L21 (context immutability): it only ever opens files in append mode and never seeks or truncates — a caller that would truncate has no method to call.

Per the issue's rule ("Port the decision, not the plumbing"), the two listed functions are ported under their names — append_line as an undefined; transport no test calls, ExperienceLine_from_hash as a tested pure constructor — and the decisions are ported with 5 tests (28 runtime asserts, 0 vacuous):

• phi_step_count / phi_step_in_order / is_valid_phi_step — the eleven-step PHI LOOP catalogue (CLAIM…PUSH, mirroring NOW.json) and the membership gate: from_hash builds the line only for an allowed step, bailing otherwise — the original's own rejects_unknown_phi_step test;
• ExperienceLine_from_hash — the built/invalid verdict with the carried fields and the absent evidence (skip_serializing_if becomes the absent flag); the clock (Utc::now) and the hash triplet arrive as parameters;
• the file layout rules — the experience directory, the trios_railway_<YYYYMMDD>.trinity daily file (prefix, suffix, compact %Y%m%d date format), one JSON record per line with its trailing newline, and the append-only contract (create(true).append(true), never truncate — L21).

Verification (all run live from the worktree root, zig 0.16.0)

• t27c parse: OK. t27c spec-status: IMPLEMENTED. t27c typecheck: 0 errors, 0 warnings.
• t27c coverage: 11/12 tested — only the append_line transport untested, by design.
• t27c test-report: 5 tests / 5 pass / 0 FAIL / 0 BLOCKED, 0 vacuous passes.
• t27c gen | grep -c 'not yet implemented': 0; gen | wc -l: 148 (> 12).
• grep -cE '^\s*(pub )?fn (ExperienceLine_from_hash|append_line)\(': 2. grep -cE '^\s*test\s+(["|[A-Za-z_])': 5 (≥ 2).
• Boundary: git status --short — exactly this one file. The repo's lefthook pre-commit passed.
• dupe_scan: all 11 names unique across 2040 specs; the bare body scan adds no duplicate group (752 bodies / 221 groups on base, identical with this spec present).

Dmitrii Fedorov (@dmitrii-f-t27)

[dmitrii-f-t27]

@gHashTag Please merge this PR into master via the golden chain — rights on gHashTag/t27 are read-only for me (403), so the merge itself needs your action.

What this is: the #9769 port — crates/trios-railway-experience/src/lib.rs (gHashTag/trios-railway, at 8b229e9489ee, 140+ lines) re-authored as specs/port/trios-railway/crates/trios-railway-experience/src/lib.t27. One file, head 01dfca17d, Closes #9769.

What is verified:

• t27c parse OK, spec-status IMPLEMENTED, typecheck 0 errors / 0 warnings, coverage 11/12 (only the append_line transport untested, by design), t27c test-report 5 tests / 5 pass / 0 FAIL / 0 BLOCKED, 0 vacuous — including the original's own rejects_unknown_phi_step test.
• gen → 148 lines, 0 not yet implemented; the 2 required names count exactly 2; 5 test blocks; boundary exactly the one file.
• dupe_scan: all 11 names unique across 2040 specs; bare body scan adds no duplicate group (752/221 unchanged).
• The t27b-native-run artifact of this head (commit 01dfca1, run 38996181282): lib.t27 row — reference pass, t27b pass, tests 5, invariants 0, asserts 28, blockers [], detail empty, reference_disagree: [].

CI (head 01dfca1): required trio green — validate, check-linked-issue, parse-ratchet; 26 checks pass overall, incl. emit-bitexact, t27b-native-linux, t27b-native-macos.

The 3 reds are the base-red trio, not this change: cli-tri (the #3324 include_str!), duplicate-bodies (only the known base names), t27b-native-ratchet (the same verdict red the Queen's port PRs carry; this spec's own row is reference pass + t27b pass — the registration debt is the UNLISTED class).

After the merge I will: verify the spec file live on the merge SHA, confirm #9769 auto-closed, and file the 14-step report.

Dmitrii Fedorov (@dmitrii-f-t27)