fix: bound the last two unbounded operational curl calls

[0xacee]

Why this matters

ODS bounds essentially every operational curl call — preflight probes, health checks, downloads, update checks — except two stragglers:

1. installers/phases/12-health.sh — after detecting Perplexica needs configuration, the phase fetches ${PERPLEXICA_URL}/api/config to learn provider UUIDs with no timeout, then pipes it into the config-push Python. A wedged Perplexica listener (container "Created", port mapped but app hung, firewall DROP) freezes install phase 12 indefinitely with the installer looking alive. The identical query 20 lines earlier in the same block already uses --max-time 5 — this site was simply missed.
2. installers/macos/ods-macos.sh cmd_chat — the ./ods-macos.sh chat command POSTs to /v1/chat/completions unbounded. A stalled local inference server or unreachable cloud endpoint hangs the user's terminal forever; every other probe in the same file uses --max-time 10.

A peer that accepts TCP but never answers is precisely the failure mode --connect-timeout alone cannot catch — --max-time is required.

What changed

• 12-health.sh: curl -sf --max-time 5 "${PERPLEXICA_URL}/api/config" — same bound as the sibling fetch above it.
• ods-macos.sh: curl -sf --connect-timeout 5 --max-time 300 -X POST ... — generous ceiling for slow CPU/cloud inference; bounds hangs, not slow responses.

No behavior change when services respond normally; failures now surface through the existing error paths (PERPLEXICA_SETUP empty → auto-setup skipped, cmd_chat → "Chat request failed.").

Regression test

ods/tests/test-curl-timeout-stragglers.sh stubs curl on PATH: the stub records argv and sleeps 30 s when --max-time is absent. It then:

• evals the real cmd_chat function body (extracted from ods-macos.sh) with stubbed ai/resolve_cli_llm_route — boundary-level proof the flags reach curl's argv;
• extracts and executes each curl ... /api/config invocation line from 12-health.sh under the stub;
• statically sweeps both files for any curl -… invocation lacking max-time/a bounds array.

Red on upstream/public-beta (15eb56fab): cmd_chat stalls → exit 124; the second /api/config fetch stalls → 124; sweep reports 1 unbounded call per file. 1 passed, 5 failed.
Green on this branch: 6 passed, 0 failed — and the already-bounded sibling fetch at :494 correctly passes, confirming the harness isn't tautological.

Validation

• bash -n both files: clean
• shellcheck -S error on both files + test: clean
• git diff --check: clean

Overlap check

Searched open/closed PRs for 12-health, ods-macos curl, curl timeout install. Closed unmerged attempts (#435, #391) were broad sweeps abandoned long ago; #1229 (merged) bounded the STT preload only. My own #6180 covers the demo scripts — disjoint files. No open PR touches these two call sites.

Notes

• Live end-to-end run against a real wedged Perplexica/cloud endpoint is pending CI/maintainer validation; the stub harness exercises the exact argv boundary curl sees.