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/RawSourceTests.swift

@@ -97,16 +97,23 @@ struct RawSourceValidationTests {
         #expect(document.value(for: "sphere") == .string("work"))
     }
 
-    @Test("The two required fields are required, with the loader's own words")
-    func schemaAndOrderAreRequired() {
-        let noSchema = validationFailure("---\ntitle: x\norder: 1\n---\nbody\n")
-        #expect(noSchema?.reason == .missingSchema)
+    /// **A card's `schema` and `order` are both optional** (01-storage-format.md § Frontmatter and
+    /// § Ordering, re-ruled 2026-07-31) — the outlet's gate is the loader's rule, so it moved with
+    /// it: a card applied without either lands at its lane's bottom, read as schema 1, and gains a
+    /// real rank on its next touch.
+    @Test("The optional fields are optional, with the loader's own rule")
+    func schemaAndOrderAreOptional() throws {
+        for text in ["---\ntitle: x\norder: 1\n---\nbody\n", "---\nschema: 1\ntitle: x\n---\nbody\n", "---\ntitle: x\n---\nbody\n"] {
+            #expect(throws: Never.self) {
+                try BoardLoader.validateCardIndex(Data(text.utf8), path: "index.md")
+            }
+        }
 
-        let noOrder = validationFailure("---\nschema: 1\ntitle: x\n---\nbody\n")
-        #expect(noOrder?.reason == .missingOrder)
+        // What still refuses: a value that is there and unreadable, and a card from a newer app —
+        // which this one has no honest way to rewrite.
+        let malformed = validationFailure("---\nschema: one\norder: 1\n---\nbody\n")
+        #expect(malformed?.reason == .malformedSchema(raw: "one"))
 
-        // The same fail-fast rule the loader applies at load: a card from a newer app is not
-        // something this one may rewrite.
         let future = validationFailure("---\nschema: 99\norder: 1\n---\nbody\n")
         #expect(future?.reason == .schemaNewerThanApp(found: 99))
     }
@@ -409,10 +416,10 @@ struct RawSourceStoreTests {
 
         let outcome = store.applyCardSource(
             inCard: ItemID(rawValue: Ident.card1),
-            text: "---\ntitle: no schema here\norder: 1\n---\nbody\n"
+            text: "---\nschema: unreadable\norder: 1\n---\nbody\n"
         )
 
-        #expect(outcome == .invalid(BoardLoadError(path: "index.md", reason: .missingSchema)))
+        #expect(outcome == .invalid(BoardLoadError(path: "index.md", reason: .malformedSchema(raw: "unreadable"))))
         #expect(try fixture.indexData(cardPath) == before)
         // The alert is the surfacing for this one — a banner as well would say the same thing twice,
         // and a write that never started is not a failed write.