fix(tokens): refresh stale "Opus 4.7" framing to model-neutral + Opus 4.8 anchor

Fase 4 token-opt, Item 1 of gap-review NEXT STEP #2. The prompt-cache pattern corpus + TOK scanner were frozen at an "Opus 4.7" framing after CC shipped Opus 4.8 (default, 2.1.154) and Fable 5 (2.1.170). Model-era facts re-verified against the official changelog cache before editing.

The patterns are properties of prompt-caching, not of any model, so mechanic text is now model-neutral with a single "current default: Opus 4.8" anchor — preventing a re-freeze at the next model bump.

- rename knowledge/opus-4.7-patterns.md -> prompt-cache-patterns.md (git mv, history preserved); 6 reference sites updated
- TOK scanner: line-318 finding text (human-facing) made model-neutral; header + cache-prefix-scanner + CLI comments refreshed
- configuration-best-practices.md body + footnote 4.7 -> 4.8
- human-facing docs: commands/{tokens,help,manifest}.md, project CLAUDE.md, README, docs/scanner-internals.md
- gap-matrix row marked DONE; future Items 2/3 retargeted to new filename

Failing-test-first (Iron Law): +2 knowledge staleness guards (era-anchor + no-refreeze) +1 scanner assertion (no stale model anchor in finding text). Suite 853 -> 856 green; zero snapshot drift; self-audit A(97) PASS. CHANGELOG / v5 plan / ratified gap-plan keep historical opus-4.7-patterns refs (correct record of past state).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Ter3E2JSi1Khgmuf2kady8
This commit is contained in:
Kjell Tore Guttormsen 2026-06-18 15:27:36 +02:00
commit 8376dab83f
15 changed files with 66 additions and 40 deletions

View file

@ -6,7 +6,7 @@
## CLAUDE.md
1. **Optimise for prompt-cache stability.** Place stable content in the first 30 lines (cache-friendly prefix); volatile content (timestamps, dynamic counts, rolling activity logs) goes below that threshold or moves to an `@import`-ed file outside the cache prefix. On Opus 4.7 the dominant cost lever is cache reuse, not file length.[^200lines]
1. **Optimise for prompt-cache stability.** Place stable content in the first 30 lines (cache-friendly prefix); volatile content (timestamps, dynamic counts, rolling activity logs) goes below that threshold or moves to an `@import`-ed file outside the cache prefix. On Opus 4.8 the dominant cost lever is cache reuse, not file length.[^200lines]
2. **Use `@import` for specs/docs.** `@path/to/spec.md` inlines the file at session start. Max 5 hops, but keep chains ≤ 2 hops — every `@import` boundary fragments the prompt-cache prefix. Keeps the main file scannable.
3. **Use HTML comments for maintainer notes.** `<!-- Updated 2026-01-01: reason -->` is stripped before context injection — zero token cost.
4. **Put personal dev notes in `CLAUDE.local.md`**, not `CLAUDE.md`. Add `CLAUDE.local.md` to `.gitignore`. Team members' sandbox URLs should never appear in git.
@ -94,4 +94,4 @@
---
[^200lines]: The "keep CLAUDE.md under 200 lines" threshold was a Sonnet-era adherence heuristic — Sonnet's attention quality dropped on longer files, so trimming raw line count was the optimisation lever. Opus 4.7 uses prompt-cache structure as the dominant cost driver: the first 30 lines must stay byte-stable across turns to keep the cache hit, and `@import` boundaries fragment the cached prefix. A 400-line CLAUDE.md with stable structure outperforms a 150-line file whose top contains a daily-rolling activity log. See `knowledge/opus-4.7-patterns.md` for detection IDs (CA-TOK-001..003).
[^200lines]: The "keep CLAUDE.md under 200 lines" threshold was a Sonnet-era adherence heuristic — Sonnet's attention quality dropped on longer files, so trimming raw line count was the optimisation lever. Opus 4.8 uses prompt-cache structure as the dominant cost driver: the first 30 lines must stay byte-stable across turns to keep the cache hit, and `@import` boundaries fragment the cached prefix. A 400-line CLAUDE.md with stable structure outperforms a 150-line file whose top contains a daily-rolling activity log. See `knowledge/prompt-cache-patterns.md` for detection IDs (CA-TOK-001..003).