fix(agent): bound video GPU work — early-exit the frame loop at max_regions

Image 81602 turned out to be a 156 MB mp4, not a huge still: the agent samples
up to 64 frames × ~32 regions/frame → ~2000 regions (the 413) and 64 frames of
detect+CCIP+embed (the 38s). The MAX_REGIONS backstop (#171) only truncated the
SUBMIT — the GPU work was already spent. Break out of the frame loop once
accumulated regions reach max_regions, so a long video costs ~a few frames of
GPU (~2-3s), not all 64 (~38s). The whole-image 'embed' task is unaffected (it
mean-pools all frames and returns before this loop).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Ttrj5P7upUTueSfoJcxEqa

agent/fc_agent/app.py

@@ -15,7 +15,7 @@ from .worker import Worker
 # Bump on every agent change. The page embeds this and /status reports it; the UI
 # warns to reload when they differ — so a stale browser-cached page can't be
 # mistaken for "the new image didn't deploy". (Belt-and-braces with no-store.)
-VERSION = "2026-06-30.9 · region-caps + active-reset"
+VERSION = "2026-06-30.10 · video region early-exit"
 
 logbuf.install()
 cfg = Config.from_env()

agent/fc_agent/worker.py

@@ -559,6 +559,12 @@ class Worker:
                         tmpl["siglip_embedding"] = vec
                         tmpl["embedding_version"] = embed_version
                         regions.append(tmpl)
+                # Stop once we have enough: a long video (image 81602 = a 156 MB
+                # mp4, 64 sampled frames × ~32 regions) would otherwise burn ~38s
+                # of GPU across every frame before the submit is even truncated.
+                # Bounds the WORK, not just the POST body.
+                if len(regions) >= self.cfg.max_regions:
+                    break
             self._record("gpu", time.monotonic() - _t_gpu)
             # Backstop: never submit an unbounded pile of regions (a pathological
             # image / long video). Keep the highest-scoring max_regions so the