docs: collapse PLAN prior-focus stack; correct M3 hash rule (D-085)

[verlyn13]

What

PLAN.md 1,579 → ~290 lines. Milestones 0-6 are kept.

Change class: A (docs) + H (one regression trap). Ledger row D-085.

Removed

The ~1,190-line superseded prior-focus stack (2026-04-22 → 2026-06-08) and the narrative bulk of §Current Focus, now capped at 20 lines.

Preserved at 3063d9f — git show 3063d9f:PLAN.md reproduces the file exactly. Naming the SHA matters; a bare git log -- PLAN.md is true but not findable.

Removed rather than archived to a second file because the content is narration, not obligation: decisions are in DECISIONS.md, designs in adr/, dated status in the housekeeping readouts. A third copy is maintenance cost.

Kept — and why the plan changed mid-flight

The intended deletion of M3-M6 was withdrawn, because its stated ground did not survive checking:

• adr/0010:19 enumerates M4's five tools — system.host.profile.v1, system.session.current.v1, system.tool.resolve.v1, system.tool.help.v1, system.policy.classify_operation.v1 — in status: accepted text.
• adr/0004 §References anchors M3's facts / fact_observations to the external research plan Appendix D.

So "M4 and M5 have no matching ADR" was false for M4, and "no design exists anywhere" was false for M3. The defensible claim was narrower — the Ring-1 producers behind those surfaces have no ADR — and it does not support deleting the blocks.

Corrected inside them

Two statements that were wrong, not merely stale:

Was	Now
M3: row_hash = sha256(prev_hash || canonical(row))	Restates adr/0064:452-456 — canonical field order, GENESIS sentinel, varint(byte_length) || field_bytes length-prefixing. The ADR forbids naive concatenation; an implementer following PLAN would have built a chain the accepted design rejects.
Eight bare just test <target> calls the justfile rejects	Annotated with the condition that activates each, now that targets are discovered from packages/*/tests.

Side effect worth noting: collapsing the file removed a doc-pointer-check: provenance-below marker, and the gate immediately caught a stale charter v1.3.0 pin the fence had been hiding. Rewritten as a floor. Removing narration made a gate more effective.

Rules and trap earned by a withdrawn commit

An earlier commit (3e9b314, dropped, never pushed) also redefined change class I by callability. Five reviewer lenses found it unmergeable. Three checklist rules and trap #61 are its residue:

1. Citations used as authorization must quote their enclosing section heading verbatim in the PR body. That commit cited adr/0057:422-423 as authorizing an ApprovalGrant mint. The line sits inside ## Out of scope → "This ADR explicitly does not authorize:", a list whose final bullet is "Ring 1 service implementation code." Quote and file:line were both accurate — only the heading carried the negation.
2. Precedence runs ADR → IMPLEMENT.md, never the reverse. adr/0077's nine class-I self-classifications cannot be relieved by editing IMPLEMENT.md. Amend the ADR; IMPLEMENT.md restates below it.
3. Charter text is quoted verbatim or not touched. That commit restated charter:54's "is live" as "exist" — which would have let a future PR argue three of invariant 7's four preconditions already exist as Ring-0 schemas.

Trap #61 scores the trajectory, not just the verdict, and carries a negative control so it cannot train "distrust all citations."

What is deferred, and why nothing is blocked

The class-I relief is relocated, not rejected — it belongs in the PR that implements the audit append, where code exercises the wording. Written ahead of that code it is an untested wording change, which is how the corpus became illegible in the first place.

Nothing waits on it. The policy-snapshot loader stands on adr/0060:325-331 (assigns it) and adr/0061:371 (specifies its checkpoint-level test obligation), needs no new ADR, and is the next lane. And with no class-I relief in flight, PLAN's M4-Month-4 architecture note is simply correct and needs no edit.

Boundary checks

• No policy duplicated into adapter/hook
• No universal shell execution added
• No audit-write agent endpoint added
• OperationShape remains upstream of CommandShape
• No schema touched; no charter text touched
• No ADR superseded, contradicted, or reclassified
• Citation discipline — no citation in this PR is used as authorization; adr/0010:19, adr/0004 §References and adr/0064:452-456 are cited as evidence that a PLAN statement was wrong, and all three sit under ## Decision / ## References / ## Context headings, not under an out-of-scope list
• Precedence — this PR amends no ADR and relieves no ADR-stated rule
• Deletion authority: D-085, with the preserving SHA named (inv-13)

Validation

just verify — green.