fix: remove legacy title section fallback

docs/ABSTRACTIONS.md

@@ -14,7 +14,7 @@ These frontmatter field names have special meaning in Laputa's UI:
 
 | Field | Meaning | UI behavior |
 |---|---|---|
-| `title:` | Human-readable title (synced with filename) | Breadcrumb, sidebar. Filename = `slugify(title).md` |
+| `title:` | Legacy display-title fallback for older notes | Used only when a note has no H1; new notes do not write it automatically |
 | `type:` | Entity type (Project, Person, Quarter…) | Type chip in note list + sidebar grouping |
 | `status:` | Lifecycle stage (active, done, blocked…) | Colored chip in note list + editor header |
 | `icon:` | Per-note icon (emoji, Phosphor name, or HTTP/HTTPS image URL) | Rendered on note title surfaces; editable from the Properties panel |
@@ -237,16 +237,17 @@ Laputa separates **display title** from the file identifier:
 
 - **Display title resolution** (`extract_title` in `vault/parsing.rs`): first `# H1` on the first non-empty body line, then legacy frontmatter `title:`, then slug-to-title from the filename stem.
 - **Opening a note is read-only**: selecting a note does not inject or auto-correct `title:` frontmatter.
-- **On rename / explicit title edits** (`rename_note`): Laputa updates both filename and `title` frontmatter atomically, plus wikilinks across the vault.
+- **Explicit filename actions** (`rename_note`): breadcrumb rename/sync actions update the filename and wikilinks across the vault. The editor body remains the title editing surface.
 - **Untitled drafts** start as `untitled-*.md` and are auto-renamed on save once the note gains an H1.
 
-### Title Field (UI)
+### Title Surface (UI)
 
-The dedicated `TitleField` is a fallback editing surface, not the canonical one:
+The BlockNote body is the only title editing surface:
 
-- If the note already has an H1, the editor body is the primary title surface and the dedicated title row is hidden.
-- If the note has no H1 and is not an untitled draft, `TitleField` appears above the editor and `onTitleSync` updates `title:` frontmatter plus the filename.
-- `TitleField` also responds to `laputa:focus-editor` events with `selectTitle: true` for new-note flows that start without an H1.
+- The first H1 is the canonical display title.
+- There is no separate title row above the editor, even when a note has no H1.
+- Notes without an H1 show the editor body and placeholder only.
+- Filename changes are explicit breadcrumb actions, not a dedicated title-input side effect.
 
 ### Sidebar Selection
 

docs/GETTING-STARTED.md

@@ -65,7 +65,6 @@ laputa-app/
 │   │   ├── WelcomeScreen.tsx     # Onboarding screen
 │   │   ├── GitHubVaultModal.tsx  # GitHub vault clone/create
 │   │   ├── GitHubDeviceFlow.tsx  # GitHub OAuth device flow
-│   │   ├── TitleField.tsx         # Editable note title above editor
 │   │   ├── ConflictResolverModal.tsx # Git conflict resolution
 │   │   ├── CommitDialog.tsx      # Git commit modal
 │   │   ├── CreateNoteDialog.tsx  # New note modal

docs/adr/0055-h1-is-the-only-editor-title-surface.md

@@ -0,0 +1,42 @@
+---
+type: ADR
+id: "0055"
+title: "H1 is the only editor title surface"
+status: active
+date: 2026-04-11
+supersedes: "0044"
+---
+
+## Context
+
+ADR-0044 moved Laputa to H1-as-title, but the frontend still carried a legacy fallback: when a note had no H1, `TitleField` and the old title section could reappear above the editor. That left two competing title surfaces in the product and made it possible for deleting an H1 to resurrect UI that was supposed to be gone.
+
+The result was both behavioral drift and stale tests: some code paths still treated the dedicated title row as a valid editing surface even though the product direction is now keyboard-first writing directly in the document body.
+
+## Decision
+
+**The editor body is now the only title surface. Laputa never renders a separate title section above the editor, regardless of whether a note currently has an H1.**
+
+Display-title behavior stays:
+1. First H1 in the body
+2. Legacy frontmatter `title:`
+3. Filename-derived fallback
+
+But the UI no longer exposes a dedicated title field for cases 2 or 3. When a note has no H1, the editor simply shows normal body content or the empty-editor placeholder.
+
+Filename operations remain explicit:
+- untitled notes still auto-rename from H1 on save
+- manual filename rename/sync remains in the breadcrumb
+
+## Options considered
+
+- **Option A** (chosen): remove the fallback title section entirely. This makes the editor honest, removes a stale code path, and keeps title editing aligned with the keyboard-first document model.
+- **Option B**: keep the fallback title field for non-H1 notes. This preserves an alternate rename path, but it reintroduces the exact dual-surface ambiguity that ADR-0044 tried to escape.
+- **Option C**: hide the title section with CSS only. Low churn, but it leaves dead render/state paths in place and makes regressions like “delete H1 and old title row returns” easy to reintroduce.
+
+## Consequences
+
+- Deleting an H1 no longer reveals any legacy title UI; the user stays in the editor body.
+- `TitleField` and the title-section render path are removed from the frontend.
+- Breadcrumb filename controls are now the only explicit file-identifier editing surface outside the editor body.
+- Older tests that asserted title editing through `TitleField` are obsolete and should be replaced by H1-title or breadcrumb-filename coverage.

docs/adr/README.md

@@ -99,7 +99,7 @@ proposed → active → superseded
 | [0041](0041-filekind-all-files-in-vault-scanner.md) | fileKind field — scan all vault files, not just markdown | active |
 | [0042](0042-trash-auto-purge-safety-model.md) | Trash auto-purge safety model | superseded → [0045](0045-permanent-delete-no-trash.md) |
 | [0043](0043-reactive-vault-state-on-save.md) | Reactive vault state: editor changes propagate immediately to all UI | active |
-| [0044](0044-h1-as-title-primary-source.md) | H1 as primary title source — filename as stable identifier | active |
+| [0044](0044-h1-as-title-primary-source.md) | H1 as primary title source — filename as stable identifier | superseded → [0055](0055-h1-is-the-only-editor-title-surface.md) |
 | [0045](0045-permanent-delete-no-trash.md) | Permanent delete with confirm modal — no Trash system | active |
 | [0046](0046-starter-vault-cloned-from-github.md) | Starter vault cloned from GitHub at runtime — no bundled content | active |
 | [0047](0047-regex-mode-for-view-filter-conditions.md) | Regex mode for view filter conditions | active |
@@ -110,3 +110,4 @@ proposed → active → superseded
 | [0052](0052-renderer-first-shortcut-execution-with-native-menu-dedupe.md) | Renderer-first shortcut execution with native-menu dedupe | active |
 | [0053](0053-webview-init-prevention-for-browser-reserved-shortcuts.md) | Webview-init prevention for browser-reserved shortcuts | active |
 | [0054](0054-deterministic-shortcut-qa-matrix.md) | Deterministic shortcut QA matrix | active |
+| [0055](0055-h1-is-the-only-editor-title-surface.md) | H1 is the only editor title surface | active |