feat(agent): navigate tool + working folder (off-scene authoring)

[winlp4ever]

What

S8 of the board-authoring plan: gives the agent a working folder — a mutable cursor, like a shell's cwd — decoupled from the user's on-screen layer. The agent can navigate into a folder and author there without moving the user's view, using the S7 headless sync intake.

Design

• ctx.rootId becomes the mutable working folder (mutated mid-turn by navigate; ctx is a stable object across tool calls, so later calls see it). Added ctx.sceneRootId = the layer the visible store projects (the user's view, fixed for the turn).
• mutatorFor(ctx) routes per call: working folder == scene layer → StoreMutator (renders + syncs, unchanged); ≠ → HeadlessMutator (off-scene).
• HeadlessMutator writes into a non-visible layer by reusing StoreMutator verbatim against a throwaway off-scene createCanvasStore seeded (from the whole-board oplog) with the target layer's content. Its local change batches are forwarded to the sync-correct intake: persistence.record + getBoardSyncRef().submitLocalBatch(batch, { scene: false }). Nothing renders; the store computes node.update.prev correctly, so no op is hand-built. clientId + id scheme match the scene store so batches/ids stay board-valid.
• navigate(target) tool (folder_id | "root" | "up"): resolves the destination, switches the working folder + write routing, and returns the folder's current contents (its ls). Listed in the agent prompt.
• link_notes resolves both endpoints in the working folder (the off-scene layer when headless), not just the visible store.
• Off-scene creates are excluded from the post-turn scene arrange/recenter (they aren't in the visible store).

Why reuse StoreMutator via an off-scene store rather than hand-build ops: node.add/edge.add are trivial, but node.update needs a correct prev slice that the store computes automatically — wrapping the store gets rewrite/patch parity and correct prev for free.

Scope

In scope: navigate + headless create/link/rewrite/patch into the working folder. Out of scope (→ S9): create_folder + per-call parent_id overrides. Deferred: mid-turn re-scoping of the search index (navigate's return is the read mechanism); an on-finish "worked in Folder X" receipt card.

Test plan

• HeadlessMutator tests: a create lands in the target layer off-scene (not in the visible store), is recorded to the whole-board oplog with the right parentId, and enters the sync intake scene:false; sessions accumulate; createLink joins two off-scene notes; a fresh session seeds from the oplog so it can rewrite a note already in that folder.
• navigate tests: entering a folder sets the working folder + routes writes off-scene; "root" restores visible writes; "up" walks to the parent; a non-folder / unknown target errors without changing the working folder.
• Full agent suite (554 tests) + npm run check-all pass.

[winlp4ever]

Review response (code-review high)

All 5 findings were valid and shared one root cause — the WRITE path was working-folder aware, but get_note / edit_note / write_note's rewrite check / arrange_notes still read the visible ctx.store. Fixed in 50480e6:

• feat(*): first commit #1–ci(github): publish github releases from workflow #3, style(ui): minor ui board twists #5 — added workingLayerStore(ctx) (the off-scene layer store when navigated away, else the visible store) and routed get_note, edit_note, write_note's existence check, and arrange_notes through it. So after navigate, the agent can read / edit / rewrite notes it just authored, and arrange_notes tidies the working folder instead of relocating the user's on-screen layer (finding ci(github): publish github releases from workflow #3 — the invariant break).
• ci(github): push release tags explicitly #4 (re-entry re-seed lag) — HeadlessMutator.ensure() now flushes persistence before re-seeding, so re-entering the same folder in one turn reflects this turn's own (debounced) writes; no overlap or broken links.

Added regression tests: off-scene read/edit/rewrite/arrange act on the working folder and never move the visible layer; re-entry sees prior writes. Prompt line broadened to say every note tool operates inside the working folder. check-all + full suites green.