feat: add title and description fields to capture grammar

Implement | prefix for titles and // separator for descriptions
across the full stack: parser, schema, API, CLI, and web frontend.

- Parser: line-aware extraction for |title, |title // desc,
  // leading desc, body // inline desc. URL-safe (skips :// lines).
  Modifiers (#tag, @time, ^card) extracted from all segments.
- Schema: ALTER TABLE migration adds title, description columns
- DB: Entity/EntityUpdate structs, all CRUD queries updated
- API: title/description on create/update/response, body validation
  relaxed (title-only entries valid)
- CLI: shows title as scan label when present
- Web: parseInput mirrors Go parser, list shows title, detail pane
  renders title + description with double-click inline editing
- Tests: 10 new cases (grammar, entity, API) — 71 total, all pass

internal/api/api_test.go

@@ -578,6 +578,115 @@ func TestAbsorbEntity_MissingSourceID(t *testing.T) {
 	}
 }
 
+func TestCreateEntity_WithTitle(t *testing.T) {
+	srv, _ := testServer(t)
+
+	resp := postJSON(t, srv, "/api/entities", map[string]any{
+		"body":        "body text",
+		"title":       "nginx trick",
+		"description": "always forget this",
+		"tags":        []string{"ops"},
+	})
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusCreated {
+		t.Fatalf("expected 201, got %d", resp.StatusCode)
+	}
+
+	var e EntityResponse
+	json.NewDecoder(resp.Body).Decode(&e)
+	if e.Title == nil || *e.Title != "nginx trick" {
+		t.Errorf("title: %v", e.Title)
+	}
+	if e.Description == nil || *e.Description != "always forget this" {
+		t.Errorf("description: %v", e.Description)
+	}
+}
+
+func TestCreateEntity_TitleOnly(t *testing.T) {
+	srv, _ := testServer(t)
+
+	title := "title only"
+	resp := postJSON(t, srv, "/api/entities", map[string]any{
+		"title": title,
+	})
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusCreated {
+		t.Fatalf("expected 201, got %d", resp.StatusCode)
+	}
+
+	var e EntityResponse
+	json.NewDecoder(resp.Body).Decode(&e)
+	if e.Title == nil || *e.Title != "title only" {
+		t.Errorf("title: %v", e.Title)
+	}
+}
+
+func TestUpdateEntity_Title(t *testing.T) {
+	srv, _ := testServer(t)
+	created := createTestEntity(t, srv, "body", nil)
+
+	req, _ := http.NewRequest("PUT", srv.URL+"/api/entities/"+created.ID, bytes.NewReader(
+		mustJSON(map[string]any{"title": "new title"})))
+	req.Header.Set("Content-Type", "application/json")
+	resp, _ := http.DefaultClient.Do(req)
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		t.Fatalf("expected 200, got %d", resp.StatusCode)
+	}
+
+	var e EntityResponse
+	json.NewDecoder(resp.Body).Decode(&e)
+	if e.Title == nil || *e.Title != "new title" {
+		t.Errorf("title: %v", e.Title)
+	}
+}
+
+func TestUpdateEntity_Description(t *testing.T) {
+	srv, _ := testServer(t)
+	created := createTestEntity(t, srv, "body", nil)
+
+	req, _ := http.NewRequest("PUT", srv.URL+"/api/entities/"+created.ID, bytes.NewReader(
+		mustJSON(map[string]any{"description": "new desc"})))
+	req.Header.Set("Content-Type", "application/json")
+	resp, _ := http.DefaultClient.Do(req)
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		t.Fatalf("expected 200, got %d", resp.StatusCode)
+	}
+
+	var e EntityResponse
+	json.NewDecoder(resp.Body).Decode(&e)
+	if e.Description == nil || *e.Description != "new desc" {
+		t.Errorf("description: %v", e.Description)
+	}
+}
+
+func TestListEntities_TitleInResponse(t *testing.T) {
+	srv, _ := testServer(t)
+
+	title := "list title"
+	postJSON(t, srv, "/api/entities", map[string]any{
+		"body":  "body",
+		"title": title,
+	}).Body.Close()
+
+	resp, _ := http.Get(srv.URL + "/api/entities")
+	defer resp.Body.Close()
+
+	var entities []EntityResponse
+	json.NewDecoder(resp.Body).Decode(&entities)
+	if len(entities) != 1 {
+		t.Fatalf("expected 1, got %d", len(entities))
+	}
+	if entities[0].Title == nil || *entities[0].Title != "list title" {
+		t.Errorf("title: %v", entities[0].Title)
+	}
+}
+
 func mustJSON(v any) []byte {
 	b, _ := json.Marshal(v)
 	return b