Consolidate PQRST drafts into spec v0.1; add prompt, intent, scope

Merge the two independent 2026-09-05 drafts under history/ into a single
normative specification at spec/PqrstEstimationPractice.md (v0.1).

Where the sources diverged on the canonical result format, the block/
signature record is adopted as the source of truth and the per-dimension
table is retained as an optional presentation form; recorded in the spec's
version history. Two rules the sources implied but did not state are added:
confidence stays outside the 5-tuple (R9), and no sixth dimension may be
introduced (R10).

Add PqrstPrompt.md in the root as the canonical end-of-session prompt,
pairing the fuller rule list with the strict fixed output block.

Add INTENT.md and SCOPE.md framing the repo as the means of closing
agentic coding sessions: why the practice exists, its anti-goals, and the
boundary that this is a specification-and-prompt repo only — no tooling,
storage, harness integration, scoring, or empirical validation.

Source drafts under history/ are retained unmodified and are append-only.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SQ6oF1DtVDKcD1FCpvRVLx

Assistant: claude-code
Assistant-Model: opus
Assistant-Process: 272883@bnt-lap001
Assistant-Session: f40c8f53-fb65-4980-9d29-bcdb3dd946f7

SCOPE.md

@@ -0,0 +1,98 @@
+# Scope
+
+This repository provides the means of **closing agentic coding sessions** using the PQRST estimation practice. It is a specification-and-prompt repository. It defines the practice, supplies the artifacts needed to perform it, and stops there.
+
+See [`INTENT.md`](INTENT.md) for why.
+
+---
+
+## In scope
+
+### 1. The specification
+
+`spec/PqrstEstimationPractice.md` — the normative definition of PQRST: the five dimensions, the estimation rules, the collection point, the canonical result formats, validation constraints, derived views, the pattern catalog, and the practice rules. Versioned; currently **0.1**.
+
+### 2. The closing prompt
+
+`PqrstPrompt.md` — the canonical end-of-session prompt, kept in the repository root so it is trivially reachable at the moment a session ends. Includes the optional add-ons and the accept/reject checklist.
+
+### 3. Record formats
+
+The stored block record, the compact signature line, the optional human-readable table, and the optional YAML form — including the validation rules that make a record well-formed.
+
+### 4. Interpretation guidance
+
+Derived views (`P+Q`, `R+S+T`), example signatures, the pattern catalog, and correlation ideas — all as hypotheses for qualitative review, never as automatic conclusions.
+
+### 5. Provenance
+
+`history/` — the source drafts from which a specification version was consolidated, retained unmodified. New drafts are added; existing ones are not edited.
+
+---
+
+## Out of scope
+
+### Tooling and automation
+
+No collectors, parsers, validators, CLIs, linters, hooks, dashboards, or storage backends live here. The record format is specified precisely enough that such tools can be built — **elsewhere**. A reference validator may be reconsidered for a later version; it is not a commitment.
+
+### Session storage
+
+This repository defines what a record looks like. It does not hold anyone's records, prescribe a database, or specify a schema for a session corpus.
+
+### Integration with any particular agent or harness
+
+PQRST is deliberately agent-agnostic and model-agnostic. Wiring it into a specific harness, plugin, skill, or CI pipeline belongs to that harness's own repository.
+
+### Scoring, benchmarking, and evaluation
+
+No thresholds, no healthy-profile templates, no grading, no leaderboards, no comparison of agents or models on PQRST values. This is excluded on principle, not for lack of time — see [`INTENT.md`](INTENT.md).
+
+### Prospective planning
+
+No effort budgets, no target allocations, no pre-session PQRST plans.
+
+### Extending the model
+
+The acronym is closed at five letters. Proposals for a sixth dimension are out of scope. Proposals to expand an existing letter into subdimensions, or to add companion fields *outside* the 5-tuple (task type, outcome, cost, module id), are in scope for a future version.
+
+### Empirical validation
+
+This repository does not claim, and does not attempt to establish, that PQRST estimates are accurate, reproducible across estimators, or predictive of outcomes. The practice is offered as a structured judgment. Studying whether it holds up is legitimate work — it is not this repository's work.
+
+---
+
+## Boundaries and invariants
+
+These hold across all versions:
+
+1. **Exactly five dimensions**, named P, Q, R, S, T, with stable meanings.
+2. **Retrospective only.** Nothing here is ever to be used as a planning target.
+3. **Records are auditable.** A signature is never published without its evidence.
+4. **Local files are the source of truth.** The specification governs; anything generated from it follows.
+5. **`history/` is append-only.**
+
+---
+
+## Repository layout
+
+```
+INTENT.md                        why this practice exists and what it must not become
+SCOPE.md                         this file
+PqrstPrompt.md                   the canonical end-of-session prompt
+README.md                        one-line orientation
+spec/
+  PqrstEstimationPractice.md     the specification (v0.1)
+history/
+  20260905-*_chatgpt.md          source draft, retained unmodified
+  20260905-*_grok.md             source draft, retained unmodified
+```
+
+---
+
+## Change process
+
+- The specification is versioned. Substantive changes increment the version and record a line in its Appendix B version history.
+- Changes that alter the meaning of a dimension, the validation rules, or the stored record format are **breaking**: they make older records less comparable, and must say so explicitly.
+- Editorial changes — clarification, examples, wording — do not require a version bump.
+- Source drafts in `history/` are never edited, only added to.