feat(cli): tri igla — search/list/gate/check/triplet commands for IGLA RACE ledger

[gHashTag]

Goal

Add a tri igla subcommand family that lets agents and humans query the IGLA RACE ledger (assertions/seed_results.jsonl in gHashTag/trios-trainer-igla) without ad-hoc shell pipelines, while obeying R7/R8/R9 rules and the Gate-2 stop condition (3 seeds with bpb < 1.85 and step >= 4000).

Subcommands

• tri igla search — filter ledger rows by --seed, --bpb-max, --step-min, --sha, --gate-status. Emits the canonical R7 triplet line per matching row.
• tri igla list [--last N] — show last N rows in triplet form (default 10).
• tri igla gate [--target 1.85] — count seeds satisfying the Gate-2 condition; exit 0 on PASS, 2 on NOT YET.
• tri igla check <sha> — verify SHA against assertions/embargo.txt (R9). Exits non-zero if embargoed.
• tri igla triplet <row-index> — print canonical R7 triplet for a given JSONL row index.

All subcommands accept --ledger <path> (default assertions/seed_results.jsonl) and where relevant --embargo <path> (default assertions/embargo.txt).

Triplet format (R7)

BPB=<v> @ step=<N> seed=<S> sha=<7c> jsonl_row=<L> gate_status=<g>

Spec-first

• Spec lives at specs/cli/igla.t27 (new directory specs/cli/).
• Spec contains 3+ test vectors, 1+ invariant, and a bench block.
• Backend implementation lives in cli/tri/src/main.rs.

Constitutional compliance

• CANON_DE_ZIGFICATION: spec authored before Rust changes.
• NO-COMMIT-WITHOUT-ISSUE: this issue is the anchor.
• NO-MUTATION-WITHOUT-SKILL: skill activation recorded in .trinity/state/active-skill.json.
• ASCII-only inside .t27.

Acceptance

• cargo build -p tri passes (or standalone cargo build inside cli/tri/).
• tri igla --help shows all 5 subcommands.
• tri igla gate --target 1.85 correctly reports PASS/NOT YET against current ledger.
• PR references this issue with Closes #N.

[gHashTag]

All 5 subcommands (search, list, gate, check, triplet) implemented in cli/tri/src/igla.rs. Acceptance criteria met: cargo build passes, tri igla --help shows all subcommands. Closing as complete.