* Raise the opencode invoke timeout in Local Agent Guides CI
The connection (opencode) cell flakes with a 600s timeout reported as guide drift, but it is not a hang: in a passing run the same opencode run finishes in ~482s (08:12:31 to 08:20:33), right against the shared AGENT_INVOKE_TIMEOUT of 600s, so about one run in six drifts past the cap.
opencode is the slow outlier. The print-mode agents (claude -p, codex exec) run one turn against a minimal injected system prompt, while opencode run runs its own full turn with opencode's large system prompt plus a separate small_model call to name the session (start.py pins small_model to the same 4B the server hosts). On a CPU-served gemma-4-E4B that is about 8 minutes, leaving no margin under 600s.
Double opencode's per-invoke timeout in agent-guides-drive.sh and keep the tight 600s cap for the fast agents, so a genuine headless-TTY hang still fails quickly. 1200s stays well under the 40-minute job budget.
* Normalize the agent invoke timeout before doubling it for opencode
Strip an optional trailing 's' from AGENT_INVOKE_TIMEOUT so the opencode
arithmetic, and the "${TIMEOUT}s" timeout message, stay valid if a
timeout(1)-style suffix is ever configured.
* Only double the opencode timeout for a bare-integer seconds value
Guard the arithmetic so a GNU timeout(1) duration suffix (s/m/h/d, including
floats like 0.5s) is passed through unchanged instead of breaking the
expansion; timeout(1) parses those directly. Bare seconds still double.
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Co-authored-by: danielhanchen <unslothai@gmail.com>