docs(gif): use the managed DSH credential store for recordings

The recording workflow currently points only to a repository .env file.
A valid key can instead live in ~/.dsh/.credentials.yaml, so missing
DEEPSEEK_API_KEY and .env do not establish that real-model recording is
blocked.

Name the managed credential source and route it through the existing
credentials-local path override when the recording uses a scratch
DSH_HOME. Preserve application-state isolation and keep secret resolution
inside the normal provider rather than printing or manually extracting
key values. This changes only recording instructions.

.agents/skills/record-browser-gif/SKILL.md

@@ -27,7 +27,7 @@ The recording itself is part of the evidence: use a real server booted from that
 A GIF for a specific pull request demonstrates that pull request's tree, so stage per pull request:
 
 1. Require a clean worktree, record its exact commit with `git rev-parse HEAD`, then build that recorded tree — here, `pnpm run build && pnpm run build:web`. A GIF recorded against another commit's build misattributes the evidence.
-2. Boot one server per port from that tree with fresh scratch `DSH_HOME`, `DSH_AGENTS_HOME`, workspace, and session state. Give the browser a fresh isolated context or profile as well; if the browser workflow cannot create one, clear that origin's cookies and site storage before navigation so persisted client state cannot affect the evidence. Source the root `.env` for the API key through the application's normal path; never echo the key.
+2. Boot one server per port from that tree with fresh scratch `DSH_HOME`, `DSH_AGENTS_HOME`, workspace, and session state. Give the browser a fresh isolated context or profile as well; if the browser workflow cannot create one, clear that origin's cookies and site storage before navigation so persisted client state cannot affect the evidence. Real API credentials can be available in `~/.dsh/.credentials.yaml` even when `DEEPSEEK_API_KEY` and the root `.env` are absent. With a scratch `DSH_HOME`, use a recording overlay to set the `dsh-credentials-local` provider's `path` to that existing file's absolute path. Let the application's normal credential provider resolve the key; never echo it.
 3. Treat one storyboard as one evidence run: every published frame comes from that server and those state roots, workspace, session, and model-backed scenario run. If capture automation fails, discard its frames and rerun from fresh roots; never splice frames from separate runs.
 4. When switching between pull requests, stop the old server by PID or an exact match on its command line. A broad `pkill -f` pattern can match and kill the shell that launched it — including your own.