feat: brain colored folders/tags — color + icon fields, mobile pills

Backend:
- Added color (hex) and icon (lucide name) columns to folders and tags
- Default folders seeded with colors: Home=green, Work=indigo, Travel=blue, etc.
- API returns color/icon in sidebar and CRUD responses
- Create/update endpoints accept color and icon

Frontend:
- Mobile: horizontal scrollable pill tabs with colored dots
- Desktop sidebar: colored dots next to folder names
- Active pill gets tinted border matching folder color

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

services/brain/app/api/taxonomy.py

@@ -22,11 +22,15 @@ router = APIRouter(prefix="/api/taxonomy", tags=["taxonomy"])
 
 class FolderIn(BaseModel):
     name: str
+    color: Optional[str] = None
+    icon: Optional[str] = None
 
 class FolderOut(BaseModel):
     id: str
     name: str
     slug: str
+    color: Optional[str] = None
+    icon: Optional[str] = None
     is_active: bool
     sort_order: int
     item_count: int = 0
@@ -34,11 +38,15 @@ class FolderOut(BaseModel):
 
 class TagIn(BaseModel):
     name: str
+    color: Optional[str] = None
+    icon: Optional[str] = None
 
 class TagOut(BaseModel):
     id: str
     name: str
     slug: str
+    color: Optional[str] = None
+    icon: Optional[str] = None
     is_active: bool
     sort_order: int
     item_count: int = 0
@@ -77,8 +85,8 @@ async def get_sidebar(
         folder_counts[row[0]] = row[1]
 
     folders = [FolderOut(
-        id=f.id, name=f.name, slug=f.slug, is_active=f.is_active,
-        sort_order=f.sort_order, item_count=folder_counts.get(f.id, 0)
+        id=f.id, name=f.name, slug=f.slug, color=f.color, icon=f.icon,
+        is_active=f.is_active, sort_order=f.sort_order, item_count=folder_counts.get(f.id, 0)
     ) for f in folder_rows]
 
     # Tags with counts
@@ -95,8 +103,8 @@ async def get_sidebar(
         tag_counts[row[0]] = row[1]
 
     tags = [TagOut(
-        id=t.id, name=t.name, slug=t.slug, is_active=t.is_active,
-        sort_order=t.sort_order, item_count=tag_counts.get(t.id, 0)
+        id=t.id, name=t.name, slug=t.slug, color=t.color, icon=t.icon,
+        is_active=t.is_active, sort_order=t.sort_order, item_count=tag_counts.get(t.id, 0)
     ) for t in tag_rows]
 
     # Total items
@@ -118,7 +126,7 @@ async def list_folders(
     rows = (await db.execute(
         select(Folder).where(Folder.user_id == user_id).order_by(Folder.sort_order, Folder.name)
     )).scalars().all()
-    return [FolderOut(id=f.id, name=f.name, slug=f.slug, is_active=f.is_active, sort_order=f.sort_order) for f in rows]
+    return [FolderOut(id=f.id, name=f.name, slug=f.slug, color=f.color, icon=f.icon, is_active=f.is_active, sort_order=f.sort_order) for f in rows]
 
 
 @router.post("/folders", response_model=FolderOut, status_code=201)
@@ -138,7 +146,8 @@ async def create_folder(
         select(func.max(Folder.sort_order)).where(Folder.user_id == user_id)
     )).scalar() or 0
 
-    folder = Folder(id=str(uuid.uuid4()), user_id=user_id, name=body.name.strip(), slug=slug, sort_order=max_order + 1)
+    folder = Folder(id=str(uuid.uuid4()), user_id=user_id, name=body.name.strip(), slug=slug,
+                    color=body.color, icon=body.icon, sort_order=max_order + 1)
     db.add(folder)
     await db.commit()
     return FolderOut(id=folder.id, name=folder.name, slug=folder.slug, is_active=folder.is_active, sort_order=folder.sort_order)
@@ -159,6 +168,8 @@ async def update_folder(
 
     folder.name = body.name.strip()
     folder.slug = slugify(body.name)
+    if body.color is not None: folder.color = body.color
+    if body.icon is not None: folder.icon = body.icon
     folder.updated_at = datetime.utcnow()
 
     # Update denormalized folder name on items
@@ -211,7 +222,7 @@ async def list_tags(
     rows = (await db.execute(
         select(Tag).where(Tag.user_id == user_id).order_by(Tag.sort_order, Tag.name)
     )).scalars().all()
-    return [TagOut(id=t.id, name=t.name, slug=t.slug, is_active=t.is_active, sort_order=t.sort_order) for t in rows]
+    return [TagOut(id=t.id, name=t.name, slug=t.slug, color=t.color, icon=t.icon, is_active=t.is_active, sort_order=t.sort_order) for t in rows]
 
 
 @router.post("/tags", response_model=TagOut, status_code=201)
@@ -231,7 +242,8 @@ async def create_tag(
         select(func.max(Tag.sort_order)).where(Tag.user_id == user_id)
     )).scalar() or 0
 
-    tag = Tag(id=str(uuid.uuid4()), user_id=user_id, name=body.name.strip(), slug=slug, sort_order=max_order + 1)
+    tag = Tag(id=str(uuid.uuid4()), user_id=user_id, name=body.name.strip(), slug=slug,
+              color=body.color, icon=body.icon, sort_order=max_order + 1)
     db.add(tag)
     await db.commit()
     return TagOut(id=tag.id, name=tag.name, slug=tag.slug, is_active=tag.is_active, sort_order=tag.sort_order)
@@ -253,6 +265,8 @@ async def update_tag(
     old_name = tag.name
     tag.name = body.name.strip()
     tag.slug = slugify(body.name)
+    if body.color is not None: tag.color = body.color
+    if body.icon is not None: tag.icon = body.icon
     tag.updated_at = datetime.utcnow()
 
     # Update denormalized tags array on items that had the old name