Docs: consolidate active planning and archive historical material

The planning package had grown to where a new agent could not tell what was
authoritative. Phase 0 execution prompts sat beside the specification; four
completed milestone reports sat beside the current one; and upstream AI-DnD's
own `plan/` build log and `docs/` project site still described a hosted,
scripted, multi-user product with accounts — every screenshot in it showed a
Scripts tab and a Sign up button, none of which has existed since M2.

`planning/archive/` now holds the history and says so in its own README:
`phase0/` for the research that chose AI-DnD, `milestone-reports/` for M1 and
M2, `decisions/` for ADR 008, the Phase-0-before-build gate Phase 0 satisfied.
`planning/reports/` holds only the current milestone's report, because that is
the one M4 planning has to read; it moves to the archive when M4's replaces it.

Deleted rather than archived: the Phase 0B execution prompts and the
handoff/status/summary documents, the Phase 0A discovery and triage reports,
upstream's `plan/` and `docs/` trees, and `frontend/README.md`, which was Vite's
template boilerplate. All of it is in Git history, and the two recommendation
reports carry every conclusion the deleted research reached.

Archived documents are kept verbatim. Paths written inside them point at where
those files were when the document was written, which is the point: an evidence
record that has been quietly edited is no longer evidence.

Active documentation is corrected where it pointed at the removed trees or
described removed capability as present. `DEVELOPMENT.md`'s "things M1 did not
touch" list had gone stale at M2 and claimed QuickJS scripting was still tested;
its test count was 604 against an actual 638. `README.md` loses the upstream CI
badge, which reported upstream's pipeline rather than this fork's, and a
reference to `backend/app/worldstate/engine.py`, a file that does not exist.
`planning/README.md` is rewritten as the documentation index.

New: `planning/PROJECT-SOURCES.md` and `planning/project-sources.txt`, the
manifest of what belongs in the ChatGPT project's Sources.

Source comments referring to the deleted trees are reworded; no behaviour
changes. 638 backend tests pass, frontend lints and builds, and a reference scan
over all 48 tracked Markdown files reports no unresolved path in active
documentation.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NCbwH7yLGKsj1rhXXzKSCu

planning/VERSION.md

@@ -1,8 +1,44 @@
 # Planning Package Version
 
-**Package:** Adventure Storyteller Planning Package v2.3  
-**Revision date:** 2026-09-03  
-**Status:** Phase 0 complete; architecture selected; **Milestones M1, M2 and M3 implemented and accepted**; M4 is next to brief.
+- **Package:** Adventure Storyteller Planning Package v2.4
+- **Revision date:** 2026-09-03
+- **Status:** Phase 0 complete; architecture selected; **Milestones M1, M2 and M3 implemented and accepted**; M4 is next to brief.
+
+## v2.4 — Documentation Consolidation (2026-09-03)
+
+No product requirement, architecture decision or milestone status changed in
+this revision. It reorganises the documentation so that a new coding agent can
+tell authoritative material from evidence at a glance.
+
+- `planning/archive/` is created and is **non-authoritative by declaration**
+  (`archive/README.md`). It holds `phase0/` — the research that chose AI-DnD —
+  `milestone-reports/` — the completed M1 and M2 reports — and `decisions/`,
+  which now holds ADR **008**, the Phase-0-before-build process gate that Phase 0
+  satisfied. ADR numbering continues from 012; 008 is not reused.
+- `planning/reports/` now holds **only the current milestone's report**,
+  `M3-IMPLEMENTATION-REPORT.md`, because M4 planning has to consult it. It moves
+  to the archive when M4's report replaces it.
+- The Phase 0B execution prompts and handoff/status/summary documents
+  (`CODEX-HANDOFF-NOTE.md`, `PHASE-0B-CODEX-BRIEF.md`,
+  `PHASE-0B-CODEX-HANDOFF.md`, `PLANNING-UPDATE-SUMMARY.md`) and the Phase 0A
+  discovery and triage reports were **deleted**: intermediate working documents
+  whose conclusions all reached the two recommendation reports, and which remain
+  in Git history.
+- Upstream AI-DnD's inherited `plan/` build log and `docs/` project site
+  (guides, generated HTML, screenshots) were **deleted**. They documented a
+  hosted, scripted, multi-user product with accounts — every screenshot showed a
+  Scripts tab and a Sign up button — which M2 removed. Both trees remain in Git
+  history and in upstream.
+- `README.md`, `DEVELOPMENT.md` and `PROVENANCE.md` are corrected where they
+  pointed at the removed trees or described removed capability as present.
+  `DEVELOPMENT.md`'s "things M1 did not touch" section had gone stale at M2 and
+  now says what is actually still inherited.
+- `planning/README.md` is rewritten as **the documentation index**: current
+  milestone, the three-way active/ADR/archive split, the authority order,
+  reading order, where reports live, and what comes next. The milestone
+  correction tables are preserved unchanged.
+- New: `planning/PROJECT-SOURCES.md` and `planning/project-sources.txt`, the
+  manifest of files to upload as ChatGPT Project Sources.
 
 ## v2.3 — Post-M3 Closeout (2026-09-03)
 
@@ -51,7 +87,7 @@ M2 removed the hosted, cloud, account and scripting surface and added the
 inference endpoint policy. Its review recommended six planning changes and
 reported rather than applied them; all six are applied in this revision, listed
 in `README.md` § *Post-M2 corrections applied*, with the evidence in
-`reports/M2-BASELINE-REPORT.md` and `reports/M2-IMPLEMENTATION-REPORT.md`.
+`archive/milestone-reports/M2-BASELINE-REPORT.md` and `archive/milestone-reports/M2-IMPLEMENTATION-REPORT.md`.
 
 In summary:
 
@@ -84,7 +120,7 @@ the architecture selected in v2 was reversed.
 M1 implementation evidence contradicted or under-specified parts of v2. The
 corrections are recorded in the documents themselves and listed in
 `README.md` § *Post-M1 corrections applied*; the evidence behind them is in
-`reports/M1-BASELINE-REPORT.md` and `reports/M1-IMPLEMENTATION-REPORT.md`.
+`archive/milestone-reports/M1-BASELINE-REPORT.md` and `archive/milestone-reports/M1-IMPLEMENTATION-REPORT.md`.
 
 In summary: