julian
f0fd15bb88
A Hikvision DS-2CD1047G3H-LIU returned HTTP 503 (statusCode 2 / deviceBusy) on EVERY main-stream snapshot — its main encoder is persistently saturated. Probed on hardware: channels/101/picture → 503 on 5 consecutive tries, while channels/102/picture (sub stream) → 200 clean JPEG every time. A retry loop can't fix a persistent busy; the real fix is stream selection. - Add a `stream` config field to the Hikvision driver (1=main, default for back-compat; 2=sub). ISAPI channel id is <channel><stream> (101 main, 102 sub). Verified live: setting the G3H to Sub flips its status degraded→ready (14.7KB JPEG in ~87ms). - captureSnapshot also retries the TRANSIENT case (503/500, linear backoff 250/500/750ms ×4) then fails naming it "(device busy)"; does NOT retry 401/404 (config errors won't self-heal). Complements captureSnapshotShared (concurrent de-dup). healthCheck still reports a live 503 as degraded (surfaces a saturated main stream rather than hiding it). Tests: camera.test.ts (10) — retry behaviour + main/sub path selection. Claude-Session: https://claude.ai/code/session_01Xcm6ikLgGoCxxHrxtjkk5V