Repair spec parser discards and reuse AST test helpers

Master 12c6d91403e58584a44d9bab39547a5b3d35b418 fails the corpus and duplicate-body ratchets on existing spec defects. These also block owner-authored PRs #8749 and #8755.

Repair scope:

specs/a/b_c.t27 and specs/a_b/c.t27: remove unmatched final braces and describe them honestly as distinct seal-path fixtures, not evidence for unrelated project acceptance criteria.
specs/compiler/optimizer.t27: two placeholder tests contain no implemented behavior, and their semicolon-commented given/then blocks account for all 84 discarded top-level tokens. Keep the deferred requirements as explicit prose and remove the nonexecuting test declarations. Do not claim a working optimizer or fix its known compiler/type blockers.
specs/tri/t27b/ast_shape.t27 duplicates the clear and mark-mask test helpers from ast_scan.t27. Export and reuse the original helpers instead of copying their bodies; preserve test assertions and function behavior.

Acceptance: all five specs parse with zero top-level discards; executable seal-path fixtures and AST specs pass their actual tests; regenerate and verify the affected seals; duplicate-body ratchet no longer reports the two added groups. No wholesale ledger blessing, handwritten foreign implementation, CI weakening, historical authorship change or unrelated placeholder coverage claim.

User Scenarios

Given the spec parser discards top-level tokens in five cited specs, when the parser runs on the corpus, then all five specs parse with zero top-level discards.
Given specs/tri/t27b/ast_shape.t27 duplicates clear and mark-mask helpers from ast_scan.t27, when the helpers are exported from ast_scan.t27 and reused in ast_shape.t27, then the duplicate-body ratchet no longer reports the two added groups.
Given specs/compiler/optimizer.t27 contains placeholder tests with semicolon-commented given/then blocks accounting for 84 discarded tokens, when the nonexecuting test declarations are removed and deferred requirements kept as prose, then the spec parses without discards and makes no claim of a working optimizer.

Requirements

FR-001: specs/a/b_c.t27 and specs/a_b/c.t27 MUST remove unmatched final braces and be described honestly as distinct seal-path fixtures.
FR-002: specs/compiler/optimizer.t27 MUST remove the two placeholder tests with semicolon-commented given/then blocks and keep deferred requirements as explicit prose.
FR-003: specs/tri/t27b/ast_scan.t27 MUST export the clear and mark-mask test helpers for reuse.
FR-004: specs/tri/t27b/ast_shape.t27 MUST import and reuse the exported helpers instead of copying their bodies, preserving test assertions and function behavior.
FR-005: All five affected specs MUST parse with zero top-level discards.
FR-006: Executable seal-path fixtures and AST specs MUST pass their actual tests.
FR-007: Affected seals MUST be regenerated and verified.
FR-008: The duplicate-body ratchet MUST no longer report the two added groups from ast_shape.t27.

Success Criteria

t27c specs/a/b_c.t27 exits 0 with zero top-level discards
t27c specs/a_b/c.t27 exits 0 with zero top-level discards
t27c specs/compiler/optimizer.t27 exits 0 with zero top-level discards
t27c specs/tri/t27b/ast_scan.t27 exits 0 with zero top-level discards
t27c specs/tri/t27b/ast_shape.t27 exits 0 with zero top-level discards
Seal regeneration for affected fixtures: .trinity/seals/parser.json updated and verified
Duplicate-body ratchet reports 0 groups for the clear and mark-mask helpers (previously 2)
Corpus ratchet passes on master branch

Boundary

specs/a/b_c.t27
specs/a_b/c.t27
specs/compiler/optimizer.t27
specs/tri/t27b/ast_shape.t27
specs/tri/t27b/ast_scan.t27
.trinity/seals/parser.json

One further master corpus failure belongs in the same spec repair: specs/port/trinity/src/tri/orchestrator_bench.t27 cannot generate Verilog because its local [10][]const u8 command array is a 2D aggregate. The function only observes the array length and each string's length; it never returns or compares command text. Replace that array with the same ten numeric lengths, preserve iteration counts and assertions, and add a length-table regression. This restores the supported representation of the existing synthetic iteration benchmark; it does not claim real command lookup, sacred score calculation or measured performance. Scope is six source specs, with regenerated applicable seals.

The remaining duplicate group is an identical same byte comparison in int_cast_plan.t27, opaque_plan.t27 and type_text.t27. The two plan specs will call the already public type_text::same, adding those two source files to this repair.

The two seal naming fixtures also derive the same a_b_c_spec.json filename. seal --save currently overwrites it without refusing, so both cannot have independently valid seals. Give the second fixture a distinct module name (no repository imports of either fixture), regenerate both separate seals, and record the general compiler collision bug separately. This repair does not claim collision protection in the compiler.

fix(specs): repair parser discards and reuse AST helpers (Refs gHashT…

fix(specs): integrate corpus parser and helper repairs (Refs gHashTag…

fix(codegen): refresh dependent Rust copies (Refs gHashTag#8756)

merge: preserve spec repairs with latest master (Refs gHashTag#8756)

Merge upstream master d2570f4 for spec repairs (Refs gHashTag#8756)

fix(specs): keep large frame arrays as byte memories (Refs gHashTag#8756

fix(specs): reconcile upstream corpus repairs (Refs gHashTag#8756)

fix(specs): refresh seal after upstream compiler repair (Refs gHashTa…

fix(specs): enroll ten verified native passes (Refs gHashTag#8756)

Merge origin/master 5e5493c into codex/spec-tests-7641 (Refs gHashTag…

fix(codegen): regenerate t27b Rust copies with the merged compiler (R…

Merge master into codex/spec-tests-7641; ledgers = master minus entri…