Add Share to L2 button for effects

- Add /effects/{cid}/publish endpoint to publish effects to L2
- Add Share to L2 button to effects detail page

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

app/routers/effects.py

@@ -316,6 +316,47 @@ async def list_effects(
     )
 
 
+@router.post("/{cid}/publish")
+async def publish_effect(
+    cid: str,
+    request: Request,
+    ctx: UserContext = Depends(require_auth),
+):
+    """Publish effect to L2 ActivityPub server."""
+    from ..services.cache_service import CacheService
+    import database
+
+    # Verify effect exists
+    effects_dir = get_effects_dir()
+    effect_dir = effects_dir / cid
+    if not effect_dir.exists():
+        error = "Effect not found"
+        if wants_html(request):
+            return HTMLResponse(f'<span class="text-red-400">{error}</span>')
+        raise HTTPException(404, error)
+
+    # Use cache service to publish
+    cache_service = CacheService(database, get_cache_manager())
+    ipfs_cid, error = await cache_service.publish_to_l2(
+        cid=cid,
+        actor_id=ctx.actor_id,
+        l2_server=ctx.l2_server,
+        auth_token=request.cookies.get("auth_token"),
+    )
+
+    if error:
+        if wants_html(request):
+            return HTMLResponse(f'<span class="text-red-400">{error}</span>')
+        raise HTTPException(400, error)
+
+    logger.info(f"Published effect {cid[:16]}... to L2 by {ctx.actor_id}")
+
+    if wants_html(request):
+        return HTMLResponse(f'<span class="text-green-400">Shared: {ipfs_cid[:16]}...</span>')
+
+    return {"ipfs_cid": ipfs_cid, "cid": cid, "published": True}
+
+
 @router.delete("/{cid}")
 async def delete_effect(
     cid: str,