Phase 10: organization & polish — cross-doc search, tags, touch, warm failures

Cross-document FTS5 search (trigram tokenizer for EN + space-free CJK, kept in
sync by triggers, back-filled from existing docs). GET /api/search uses the FTS
index for queries >=3 runes and a LIKE fallback for 1-2 (so 2-char Chinese words
resolve); snippets are built in Go with rune-aware boundaries and sentinel
highlights.

Tags: user-scoped tags + document_tags join (both cascade), idempotent
create/assign, per-tag doc counts. Doc list and search carry each doc's tags
(one tagsByDoc query). Frontend: useTags, TagChip/TagPicker/SearchBox, rewritten
DocList with chips + filter bar + search.

Tablet/touch: responsive sidebar drawer (hamburger + scrim <768px), coarse-
pointer tap targets, tap-to-open + outside-pointerdown-close for suggestion
cards.

Warm LLM-down state: useCheckpoint llmDown flag drives a gentle bilingual
StatusBar note (writing still saves locally).

Migration 0004 (tags + FTS). Tests: tags lifecycle, search EN/CJK/LIKE/update-
reindex. go build/vet/test, tsc, vite all clean; verified live on deployment host.

Claude-Session: https://claude.ai/code/session_016Yr6jELuRc7hyzYLccQKZd

internal/db/models.go

@@ -51,6 +51,29 @@ const (
 	VersionKindPreRestore = "pre_restore" // safety copy taken just before a restore
 )
 
+// Tag is a user-scoped label for organizing documents. `Color` is a palette key
+// (rose, mint, peach, lavender, sky, honey) the frontend maps to a CSS color;
+// storing the key (not a hex value) keeps tags in step with the design tokens.
+// `DocCount` is populated only by the tag-list endpoint (how many documents wear
+// the tag); it's omitted from per-document tag lists.
+type Tag struct {
+	ID       string `json:"id"`
+	Name     string `json:"name"`
+	Color    string `json:"color"`
+	DocCount int    `json:"doc_count,omitempty"`
+}
+
+// Tag color palette keys, mirrored on the frontend. Kept small and aligned with
+// the existing design tokens; unknown values fall back to rose client-side.
+const (
+	TagColorRose     = "rose"
+	TagColorMint     = "mint"
+	TagColorPeach    = "peach"
+	TagColorLavender = "lavender"
+	TagColorSky      = "sky"
+	TagColorHoney    = "honey"
+)
+
 // Suggestion is a single LLM-proposed edit anchored to a span of the document.
 //
 // FromPos/ToPos are plaintext offsets into ContentText for server-side use only;