Add IPFS node to L2 for federated content storage

- Add IPFS container to docker-compose
- Add ipfshttpclient dependency
- Add ipfs_client.py module for IPFS operations
- Add ipfs_cid field to Asset model and database schema
- Pin content on L2 IPFS when assets are published/registered

L2 now stores content on its own IPFS node, enabling
federation - content remains available even if L1 goes down.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

server.py

@@ -86,6 +86,7 @@ class Asset(BaseModel):
     """An owned asset."""
     name: str
     content_hash: str
+    ipfs_cid: Optional[str] = None  # IPFS content identifier
     asset_type: str  # image, video, effect, recipe, infrastructure
     tags: list[str] = []
     metadata: dict = {}
@@ -108,6 +109,7 @@ class RegisterRequest(BaseModel):
     """Request to register an asset."""
     name: str
     content_hash: str
+    ipfs_cid: Optional[str] = None  # IPFS content identifier
     asset_type: str
     tags: list[str] = []
     metadata: dict = {}
@@ -125,6 +127,7 @@ class RecordRunRequest(BaseModel):
 class PublishCacheRequest(BaseModel):
     """Request to publish a cache item from L1."""
     content_hash: str
+    ipfs_cid: Optional[str] = None  # IPFS content identifier
     asset_name: str
     asset_type: str = "image"
     origin: dict  # {type: "self"|"external", url?: str, note?: str}
@@ -1613,11 +1616,21 @@ async def _register_asset_impl(req: RegisterRequest, owner: str):
     if await db.asset_exists(req.name):
         raise HTTPException(400, f"Asset already exists: {req.name}")
 
+    # Pin content on IPFS if CID provided
+    if req.ipfs_cid:
+        try:
+            import ipfs_client
+            if ipfs_client.is_available():
+                ipfs_client.pin(req.ipfs_cid)
+        except Exception as e:
+            logger.warning(f"Failed to pin IPFS content {req.ipfs_cid}: {e}")
+
     # Create asset
     now = datetime.now(timezone.utc).isoformat()
     asset = {
         "name": req.name,
         "content_hash": req.content_hash,
+        "ipfs_cid": req.ipfs_cid,
         "asset_type": req.asset_type,
         "tags": req.tags,
         "metadata": req.metadata,
@@ -1735,11 +1748,21 @@ async def publish_cache(req: PublishCacheRequest, user: User = Depends(get_requi
     if await db.asset_exists(req.asset_name):
         raise HTTPException(400, f"Asset name already exists: {req.asset_name}")
 
+    # Pin content on IPFS if CID provided
+    if req.ipfs_cid:
+        try:
+            import ipfs_client
+            if ipfs_client.is_available():
+                ipfs_client.pin(req.ipfs_cid)
+        except Exception as e:
+            logger.warning(f"Failed to pin IPFS content {req.ipfs_cid}: {e}")
+
     # Create asset
     now = datetime.now(timezone.utc).isoformat()
     asset = {
         "name": req.asset_name,
         "content_hash": req.content_hash,
+        "ipfs_cid": req.ipfs_cid,
         "asset_type": req.asset_type,
         "tags": req.tags,
         "description": req.description,