Realign code with the 2026-07-31 findings-resolution rulings

The full bullet list from Implementation card bf080d9a — both ruling
batches, including the three appended mid-session by 16ef377:

- Restore subjects compose the inverse, never nest: crossing "Undo: S"
  emits "Redo: S" and vice versa; parity, not stack depth, reads a
  legacy double prefix (GitHistoryProvider.restoreSubject).
- Git-operation failures join the one-shot failure banner tier:
  BannerCenter.GitFailureBanner (undo/redo/branchSwitch/addGit), error
  tone at failure rank merged with write one-shots by recency; the
  postLoss compromise is retired at both AppModel wirings.
- order/schema optional below the board root: append-at-end reading
  (ordered siblings first, folder-name tie-break among the order-less),
  schema reads 1, both coerce-tier logged; the root keeps its
  requirements. Ranks.resolvedOrders materializes finite ranks so
  models and placement math stay untouched; first Writer rewrite
  stamps a real rank on touch, placement against an order-less sibling
  stamps that sibling inline in the same bracket. Agent guide v10
  teaches optional keys and zero-read filing. Hostile-YAML order
  shapes become coercion tests; Fixtures/Valid/optional-keys.kanban
  replaces the four retired Malformed boards.
- .gitignore is the relocation-heal noise gate: GitignoreRules pure
  matcher (standard semantics, board-root file only), loader consults
  it once per walk so matched loose files keep the stray posture;
  seeded (.DS_Store + .*.lanework-*) at board creation and template
  instantiation, healed in when missing at open — repo-nested
  included; empty file honored, existing files never edited; the
  committer's obedience via libgit2 status is pinned by test.
- Comments crash-residue sweep gates on step ownership: HistoryStep
  derives backing from its own undo expectations, backedContent unions
  both stacks, the sweep purges per-entry only what no live step owns.
- Skip-purge decoupled (16ef377): a stale-skipped coarse step strands
  whole in NativeHistoryProvider.strandedSteps — still backing, retired
  only at session end; clean exits purge as before.
- Coarse close step named "Changes to '<card>'"; the fine body-edit
  wording never leaks onto the board menu.
- Branch-switch settle clears every open card window's fine stack on
  Save All and Discard alike; the empty fold registers no coarse step.
- Close flush awaits its covering snapshot (quiesce + one generation
  bump, 1s bound), and an explicit flush now queues behind an
  in-flight one instead of skipping — the audit-caught interleaving
  could lose a close flush permanently when the debounce fired inside
  the close sequence; regression tests force both races.
- Commit comment bullets sort chronologically by created, not UUID.
- The production-unwired CardBodyEditSession.editSessionDidChange seam
  is deleted with its seam-only tests.
- Composition-root pins: beginSession composes the committer with the
  store's own EchoLedger and binds the announcer (the miswire class).
- Deliberate 06 conformance pass over every 2026-07-31-tagged
  sentence: fixed Change-custom-key subjects (the retired named
  generic was the only producer), the unbuilt Replace attachment
  vocabulary, heal commits now authored Lanework Integrity, the config
  reader scopes identity to plain [user] sections, add-git re-runs
  detection at create (a stale mode-none could initialize inside the
  user's repo), and add-git failures answer at the form or the banner.
  Structural residue filed on the Redesign board.

2554 tests / 439 suites green.

Claude-Session: https://claude.ai/code/session_01CqjXB7ASoWtbyoGod68k97

KanbanTests/AgentGuideTests.swift

@@ -22,10 +22,18 @@ import Testing
 // MARK: - Shared fixtures
 
 /// A one-lane board — enough tree that a reload has something to walk.
+///
+/// It carries the **seeded `.gitignore`**, which is what any board the app has opened once looks
+/// like (06-history-undo.md ▸ Repository hygiene, re-ruled 2026-07-31). Without it the store's own
+/// seeding heal — which runs on every successful reload beside this file's guide refresh — would
+/// write that file on the first reload and open a bracket of its own, and the bracket counts below
+/// would stop being claims about the guide. (`LooseFileRelocationTests`' fixture carries the guide
+/// for the mirror-image reason.)
 @MainActor
 private func makeBoard() throws -> WriterFixture {
     let fixture = try WriterFixture()
     try fixture.item("", Item.board)
+    try fixture.file(IntegrityRules.gitignoreFileName, Data(BoardWriter.gitignoreSeed.utf8))
     try fixture.item(Ident.lane1, Item.rich(order: "1024", title: "Todo"))
     return fixture
 }
@@ -721,6 +729,31 @@ struct AgentGuideContentTests {
         #expect(content.contains("quoted value left unclosed across a"))
     }
 
+    /// **v10: the zero-read minimum** (01-storage-format.md § Frontmatter and § Ordering, re-ruled
+    /// 2026-07-31). 08-agent-integration.md's masterplan requirement — "filing a card must need
+    /// nothing but the schema" — was untrue while a card needed a rank, because a rank needed a scan
+    /// of every sibling in the lane. The guide has to teach both halves: the short form is legal and
+    /// lands at the bottom, and *writing* `order` is still the only way to choose a position.
+    @Test("v10 teaches optional keys and the zero-read minimum")
+    func v10OptionalKeyVocabularyIsPresent() {
+        let content = AgentGuide.content
+        // The keys are optional below the root, and the root's `schema` is not.
+        #expect(content.contains("**required at the board's own `index.md`**"))
+        #expect(content.contains("optional below it — a lane or card without one is read as schema 1"))
+        #expect(content.contains("**optional, and the way to control position**"))
+        // The minimum card, and where it lands.
+        #expect(content.contains("**You can also file a card without reading the lane at all.**"))
+        #expect(content.contains("no `order`, no `schema`"))
+        #expect(content.contains("It lands at the bottom of the lane"))
+        #expect(content.contains("the app\nwrites a real `order` into it"))
+        // Reading order names the rule the minimum card depends on.
+        #expect(content.contains("An item with no\n  `order` sorts after every item that has one"))
+        // Hard rules no longer calls either key required below the root.
+        #expect(content.contains("`schema` and `order` are optional and a\n  missing one is read, never refused"))
+        #expect(!content.contains("Lanes and cards additionally require `order`"))
+        #expect(!content.contains("plus `order` on lanes and"))
+    }
+
     /// The pathfinder's guide taught `media/` and tombstone deletes; both are retired
     /// (01-storage-format.md ▸ Changes from the pathfinder schema; ▸ Deletion). The one legitimate
     /// mention of `deleted:` is the warning never to write it.