chore(memory): BDR-048 pinned-gate doctrine + LRN-092 SAST smoke-test + journal 2026-07-03

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XpphkdTosUzokBDNG7PToS

.claude/memory/learnings.md

@@ -109,6 +109,7 @@ rules:
 | LRN-087 | 2026-07-02 | presence-flag ≠ capability — rtk silently dead after .bashrc wipe; emitted commands need ABSOLUTE bin paths (they run in another shell); integrity pin = live machinery, re-pin on hook edit | any PATH-dependent capability + hand-managed shell profile; hooks emitting commands for another shell |
 | LRN-088 | 2026-07-02 | token-cutting intuition inverts under measurement — verbosity beats cardinality (gstack 34 skills ≈ 592 tok vs pr-review 6 agents ≈ 2,183) | any "disable X to save tokens" — measure per-item bytes first; profiles toggle skills, not plugin payloads |
 | LRN-089 | 2026-07-03 | pass-through wrapper (CLI `"$@"` → fn deriving target from ambient state: HEAD/cwd/env) silently ignores its args = silent contract violation; guard = args are an ASSERTION, refuse when they disagree with state | any dispatcher forwarding args to a callee that reads ambient state instead of the args |
+| LRN-092 | 2026-07-03 | SAST smoke test w/ the OFFICIAL example secret = vacuous pass (rules exclude documented example keys by design); validate w/ realistic payloads + measure tier coverage before trusting a gate ruleset | smoke-testing any detector/gate — never the canonical example payload |
 
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@@ -977,3 +978,9 @@ rules:
 - **rule**: keep a token BARE only when its UI sense dominates largely in a dev context (glassmorphism, navbar). Token common in non-UI talk (design, component, theme, transition, frontend) → require a UI-specific bigram (design system, front-end design) or drop; in doubt → bigram-or-drop. Borderline standalone nouns (dashboard, animation) may stay bare as an assumed call — the fire-log arbitrates later on data, not gut. (NOT "never bare tokens" — animation stays bare here by design.)
 - **context**: design-toolchain-reminder.sh — 07-02 tightening (dropped page/form/menu/…) insufficient; 6 bare tokens still false-fired ~6×/session during the ECC config audit (design, ecc_dashboard.py, component, frontend, theme, transition, palette). 07-03 fix: dropped them, dashboard→`\bdashboard\b` (filename match killed, "admin dashboard" kept), added a fire-log (time+token+excerpt). `lib/tests/design-toolchain-reminder.test.sh` locks it (18 checks).
 - **cousin**: [[LRN-047]] a doctor that cries false is ignored.
+
+## LRN-092 — SAST smoke test: official example keys are rule-excluded — "no findings" proves nothing
+- **pattern**: smoke-testing a SAST/secret detector w/ the OFFICIAL example payload (AWS `AKIA...EXAMPLE`) → 0 findings BY DESIGN — rules exclude documented example keys to kill FP. A vacuous pass, [[LRN-048]] class (a pass must prove it looked). Validate w/ realistic-shaped payloads AND enumerate what the tier does NOT catch before trusting a ruleset as a gate.
+- **context**: lot 1 semgrep-install dogfood 2026-07-03. `p/secrets`+`p/security-audit` community tier: anonymous fetch OK (52 rules, no login), `subprocess-shell-true` detected ERROR; MISSED %-format SQLi on bare cursor (no recognized DB-API context) + fake-checksum `ghp_` token. Gap logged for security-auditor agent design (consider adding `p/owasp-top-ten`).
+- **future application**: any detector/gate smoke test — craft realistic payloads, never the canonical example; measure the miss-list on purpose-built fixtures; size the gate's blocking scope on that data.
+- **cousin**: [[LRN-048]] a 0/OK must prove it looked; [[LRN-047]] noisy guard = ignored guard; conditions [[BDR-048]].