chore(memory): BDR-097 graphify threshold, LRN-162 graphify measurements, journal + TODO 2026-09-24

.claude/memory/learnings.md

@@ -1520,3 +1520,10 @@ Rule: when editing a doctrine file under structure locks, grep the test's lock s
 - **Pattern**: (a) a safety check whose reference point is configurable changes meaning when config moves elsewhere — auto-push broke `-d` with zero diff in the delete code. Verify "merged" explicitly against the NAMED base: `git merge-base --is-ancestor <br> <base>`. (b) probing a guardrail inline gets blocked BY the guardrail: deny strings (`core.hooksPath`, `GIT_CONFIG_GLOBAL=`, `rm -rf "$VAR"`, `branch -D develop`) are matched in the command text, heredocs included → 4 denials this session. Probe = a test in the suite (file, run via `make test`), the TDD path anyway; file content via the Write tool, command line clean. (c) `reference-transaction` hook: line `<old> <new> <ref>` in `prepared`; `branch -d` passes an all-zero old oid ("force" semantics) → ref NAME + all-zero NEW is the only reliable deletion signal; a merged check cannot live there.
 - **Future application**: any change to upstream/push config → re-read every `-d`, `--ff-only`, `@{u}`-relative guard. New destructive capability → static deny + mechanical check + prose, in that order ([[LRN-160]]). Guardrail probes → test file, never inline; a denied probe is the guard working, not a bug to route around.
 - **Reference**: [[BDR-096]], [[BDR-095]], `lib/gitflow-test.sh` T22a/T23, git-branch(1), githooks(5) reference-transaction.
+
+## LRN-162 — graphify measured: free AST map, paid semantic pass, 2-3k tokens per query, noise from `.claude/`
+- **Date**: 2026-09-24
+- **Context**: user asked whether graphify saves context ("agents re-read the whole codebase per feature"). Built the graph of a scratch copy of robin_petier (PHP, 295 files) with the CLI only: `graphify update .` (no skill pipeline, no LLM).
+- **Pattern**: (a) code-only build 2.3 s, 0 tokens, 3141 nodes / 7241 edges / 199 communities; hubs correct without any LLM (Auth, Database, Router, PDO, PHPMailer). Incremental update 1.9 s. `graphify-out/` = 8 MB (graph.json 4.4 + graph.html 3.5) → gitignore it. (b) one `graphify query` ≈ 2000-3000 tokens (default budget 2000, over-budget answers spill; truncation at 70/245 nodes on broad questions) = the price of two file reads; it maps (name, file:line), it does not replace reading the file you edit. Value = localisation, not editing. (c) it indexed `.claude/` (contracts, PROCEDURE.md, registries): an "authentication" query surfaced a mobile-nav contract → `.graphifyignore` (`.claude/`, `docs/superpowers/`; gitignore semantics, can only exclude more). (d) 13 `.sql` files contributed nothing: `tree_sitter_sql` missing → `pipx inject graphifyy "graphifyy[sql]"`. (e) `update` refuses to write a graph with FEWER nodes unless `--force`/`GRAPHIFY_FORCE=1` → after a refactor that deletes code, an automated update goes stale silently. (f) `graphify hook install` targets the repo's hooks dir; under our global `core.hooksPath` it is inert → our generated post-commit hook is the only integration point. (g) `graphify claude install` = PreToolUse nudges on every Read/Glob + CLAUDE.md rewrite — the context tax itself. (h) the semantic pass (docs/papers) runs on the host agent = session tokens; code-only stays free.
+- **Future application**: measure a "context saver" before adopting it — build time, artifact size, tokens per use, noise sources. Threshold rule [[BDR-097]]: propose from 200 tracked code files, never below. Pilot recipe when the user says go: `graphify update .` + `.graphifyignore` + gitignore `graphify-out/` + `GRAPHIFY_FORCE=1 graphify update .` in the post-commit hook, guarded by `[ -f graphify-out/graph.json ]`.
+- **Reference**: [[BDR-097]], [[BDR-028]], `lib/graphify-gate.sh`, graphify 0.9.65 (`detect.py` `_SKIP_DIRS`, `.graphifyignore`; `hooks.py` core.hooksPath handling; `__main__.py` PreToolUse nudge payloads).