Document Pathfinder and community feedback across the contributor docs

Moves the README's deep material into .readme/ (walkthrough, autonomous
loop, status line, metrics, test bot) and brings AGENTS.md, the .agents-docs
set and QUICK-REFERENCE.md in line with Step 0 and the metrics ingestion
flow.

AI Assisted

.agents-docs/AGENTS-code-style.md

@@ -17,4 +17,6 @@
 - **Workflow file character limit:** All `src/plan2code-*.md` files must be ≤ 11,000 characters. A husky pre-commit hook enforces this. The 11,000 limit leaves buffer for platform-specific YAML headers (106-142 chars) to stay under Windsurf's 12,000 char limit.
 - **Metrics internal prompts have no char limit:** Files in `plan2code-metrics/src/prompts/` are NOT subject to the 11,000 char limit — only `src/plan2code-*.md` consumer-facing prompts are.
 - **User Feedback table format:** The `## User Feedback` markdown table in `overview.md` has a strict format the collector regex depends on. Field names must be exactly `Rating`, `Reason`, `Went Well`, `Went Poorly`. Pipe characters in values must be escaped as `\|`.
+- **PLAN-DRAFT confidence numbers are scraped by regex:** when a `specs/<feature>/PLAN-DRAFT-*.md` contains no `<!-- METRICS_JSON ... -->` comment, `collector.ts` falls back to prose scraping (`collector.ts:186-241`). The overall-confidence pattern requires a literal `%`, but the four *breakdown* patterns (`collector.ts:201-204`) do **not** — `/[Rr]equirements?[:\s|]+(\d{1,2})/` and its siblings match a bare dimension word followed by whitespace, a colon, or a pipe and then digits. So a PLAN-DRAFT written by anything other than `/plan2code-1-plan` Phase 7 must keep both the `%` sign **and** bare `Requirements` / `Feasibility` / `Integration` / `Risk` followed by a number off the page — including innocent table rows like `| Requirements | 11 |`. Otherwise the metrics pipeline records a planning-step confidence that no planning step produced. `/plan2code-0-pathfinder` works around this by hyphenating the labels (`Requirements-clarity 22/25`), which breaks the character class.
 - **Reference file sizing guideline:** Files in `src/plan2code-*-references/` directories target ~100-200 lines each (soft guideline; evaluate splitting above 300). They are NOT subject to the 11,000 character limit. The pre-commit hook (`validate-char-count.js`) only checks `src/plan2code-*.md` flat files — subdirectory contents are automatically excluded.
+- **The splitting guideline has a hard ceiling — reference files cannot always be split:** two constraints bound it. (1) Each new reference costs the orchestrator a column-0 `Read references/<file>.md` line plus its fallback blockquote (~150-200 chars), and orchestrators near the 11,000 limit have no room to spend. (2) **The path rewrite is not recursive** — `syncPrompts()` rewrites `Read references/…` paths on the *orchestrator's* content only, so a `Read references/…` directive placed *inside* a reference file is never rewritten for flat-file targets; it ships as a dangling instruction pointing at a path that does not exist there. When a reference legitimately exceeds 300 lines (e.g. `plan2code-0-pathfinder-references/chart.md`), that is an accepted trade-off, not an oversight.