docs(#2775): align package-legitimacy docs to the ADR-0656 registry-API gate (#3010)

* docs(#2775): align package-legitimacy docs to the ADR-0656 registry-API gate

security-model.md, USER-GUIDE.md, ARCHITECTURE.md, COMMANDS.md,
FEATURES.md, and gsd-planner.md's STRIDE template (+ ja-JP mirrors)
described the pre-ADR-0656 design: slopcheck as the install-or-degrade
gate, with unavailability degrading every package to [ASSUMED].
ADR-0656 inverted this months ago — registry-API verdicts (npm/PyPI/
crates.io) are the gate; slopcheck is an optional escalate-only adapter
that no shipped configuration wires. Verified every replacement claim
against src/package-legitimacy.cts (checkPackages, classifyPackage,
lookupNpm/lookupPypi/lookupCrates) via Memtrace before writing it, so
the corrected prose matches the live implementation rather than
restating the ADR from memory.

Restored docs/explanation/security-model.md:79-84 (and its ja-JP
mirror) to original wording after an orthogonal spec review caught
that an earlier draft had edited the "Why WebSearch packages are
always [ASSUMED]" paragraph — inside the range issue #2775 explicitly
named as correct and to leave alone.

The ja-JP mirror was missing the closing clause present in the
corrected English original ("its absence leaves registry-API verdicts
intact rather than downgrading everything to [ASSUMED]") — added for
parity. This completes the ja-JP mirror the issue's acceptance
criteria named explicitly.

zh-CN/ko-KR/pt-BR (not named by #2775, but carrying the same stale
design) get the mechanical portion of the same fix: command-string
swaps, table headers, ARCHITECTURE.md diagram labels, and technical-
term swaps that reuse a word already attested elsewhere in the same
file (合法性/적법성/legitimidade for "legitimacy") — surrounding prose
untouched. The remainder in those three locales — full-paragraph
rewrites of the corrected degrade-path mechanism, deleted "External
dependency" bullets, and "manually install slopcheck" code blocks —
needs prose composed by a fluent speaker of each language and is filed
as open-gsd/gsd-core#3002 with an exact file:line inventory.

* test(#2775): acknowledge gsd-planner.md byte growth from the STRIDE-row fix

agents/gsd-planner.md grew 14 bytes (49309 -> 49323) from the STRIDE
supply-chain row correction (slopcheck -> package-legitimacy gate).
Emitted agent/workflow files are byte-tracked; this fragment
acknowledges the growth per tests/emitted-attribution.test.cjs's
"differential attribution over the real tree" check.

* docs(#2775): close ja-JP FEATURES.md gap; fix a ko-KR transliterated heading

docs/ja-JP/FEATURES.md:2808 still read the katakana transliteration
"スロップチェック verdict" in REQ-PKG-GATE-01 — invisible to a literal
"slopcheck" grep, so it was missed when ja-JP parity was checked and
declared complete. Corrected to "正当性判定" (legitimacy verdict),
matching the term already established in ja-JP/explanation/
security-model.md and ja-JP/USER-GUIDE.md. This was the only
remaining ja-JP gap; a full sweep for the transliterated form across
docs/ja-JP/ now returns zero hits, and the ja-JP mirror is genuinely
at parity.

docs/ko-KR/USER-GUIDE.md:398's heading "슬롭체크 판정:" had the same
transliteration problem. Fixed inline to "적법성 판정:", reusing the
적법성/legitimacy word already attested two lines below in the same
table. A parallel sweep of zh-CN and pt-BR found no transliterated
forms of "slopcheck" in either locale. The remaining transliterated
occurrence in ko-KR (USER-GUIDE.md:406, the lead-in to the
pip-install code block) needs prose composition like the rest of that
block and is added to open-gsd/gsd-core#3002's inventory.

* chore(#2775): backfill changeset PR number to 3010

---------

Co-authored-by: sim <sim@local>

docs/ARCHITECTURE.md

@@ -579,7 +579,7 @@ ui-phase → UI-SPEC.md (design contract, optional)
 plan-phase
     ├── Research gate (blocks if RESEARCH.md has unresolved open questions)
     ├── Phase Researcher → RESEARCH.md
-    │       └── Package Legitimacy Gate: slopcheck on every package; [SLOP] removed,
+    │       └── Package Legitimacy Gate: registry-API verdict on every package; [SLOP] removed,
     │           [SUS]/[ASSUMED] flagged; Audit table written to RESEARCH.md
     ├── Planner (with reachability check) → PLAN.md files
     │       └── checkpoint:human-verify injected before [ASSUMED]/[SUS] installs;
@@ -845,17 +845,15 @@ The researcher → planner → executor pipeline includes a supply-chain gate ag
 
 | Layer | Component | Action |
 |-------|-----------|--------|
-| Research | `gsd-phase-researcher` | Runs `slopcheck install <pkgs> --json`; writes `## Package Legitimacy Audit` table to RESEARCH.md; strips `[SLOP]` packages before RESEARCH.md is written |
+| Research | `gsd-phase-researcher` | Runs `gsd-tools query package-legitimacy check --ecosystem <npm\|pypi\|crates> <pkgs>`; writes `## Package Legitimacy Audit` table to RESEARCH.md; strips `[SLOP]` packages before RESEARCH.md is written |
 | Planning | `gsd-planner` | Reads Audit table; inserts `checkpoint:human-verify` before any `[ASSUMED]` or `[SUS]` install task; adds `T-{phase}-SC` STRIDE supply-chain row to `<threat_model>` |
 | Execution | `gsd-executor` | RULE 3 excludes package installation from auto-fix scope; failed installs surface as checkpoints, never silent substitutions |
 
-**Claim provenance integration:** Package names discovered via WebSearch are tagged `[ASSUMED]` (not `[VERIFIED]`) regardless of `npm view` result. This extends the existing `[ASSUMED]` / `[VERIFIED]` / `[CITED]` provenance system by enforcing the provenance tag as a hard gate at the install boundary — `[ASSUMED]` always generates a `checkpoint:human-verify` in PLAN.md.
+**Claim provenance integration:** Package names discovered via WebSearch are tagged `[ASSUMED]` (not `[VERIFIED]`) regardless of the registry-API verdict. This extends the existing `[ASSUMED]` / `[VERIFIED]` / `[CITED]` provenance system by enforcing the provenance tag as a hard gate at the install boundary — `[ASSUMED]` always generates a `checkpoint:human-verify` in PLAN.md.
 
-**Ecosystem coverage:** The researcher uses registry-specific verification commands — `npm view` (Node), `pip index versions` (Python), `cargo search` (Rust) — rather than a single generic check. This catches cross-ecosystem hallucination (~9% rate documented in 2025 USENIX research).
+**Ecosystem coverage:** The gate resolves signals directly from each ecosystem's registry API rather than a single generic check — `registry.npmjs.org` + `api.npmjs.org/downloads` (Node), `pypi.org/pypi/<pkg>/json` (Python), the crates.io API (Rust). This catches cross-ecosystem hallucination (~9% rate documented in 2025 USENIX research).
 
-**Graceful degradation:** If `slopcheck` is unavailable, every recommended package is tagged `[ASSUMED]` and gated with a checkpoint. Research and planning proceed; the system never hard-fails on a missing tool dependency.
-
-**External dependency:** `slopcheck` (MIT, pip-installable). If abandoned, the `[ASSUMED]`-gate fallback maintains human-checkpoint coverage.
+**Graceful degradation:** Each registry adapter degrades to null signals (never throws) on a failed lookup; missing signals push a package to `[SUS]`, which is gated behind the same `checkpoint:human-verify` checkpoint as `[ASSUMED]`. Research and planning proceed; the system never hard-fails on a network or tool outage. `slopcheck` is an optional escalate-only adapter — it can only raise a verdict, never lower it, and is not the install-or-degrade gate. No shipped configuration wires it.
 
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