…fetches

The lock owner now touches the lock file every 30s so waiters can
distinguish a slow-but-healthy pagination (e.g. 200k tests over many
pages with 20s timeouts + retries) from a crashed owner. Without this,
a fetch exceeding 2 minutes would be misclassified as stale, causing
waiters to break the lock and fetch concurrently — defeating the
deduplication on exactly the large payloads it exists to protect.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Integration tests reuse the same mock server port within a file with
different known tests data per test case. The cache would return stale
data from a previous test, causing timeouts.

Add DD_CIVISIBILITY_KNOWN_TESTS_CACHE_DISABLED env var (default false)
and set it in getCiVisAgentlessConfig/getCiVisEvpProxyConfig helpers.
When set, getKnownTests bypasses cache entirely and fetches directly.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

…KNOWN_TESTS_CACHE_ENABLED

Rename env var and flip the default: cache is now off unless explicitly
enabled. This avoids interference with integration tests (no env var
needed in test helpers) while letting monorepo users opt in for the
deduplication benefit.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

The env var is a string — '!!value' treats 'false' and '0' as truthy.
Use isTrue() which correctly handles 'true'/'1' vs 'false'/'0'.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

readFromCache now rejects entries where the data field is undefined or
null. This prevents stale cache files written with an older format
(e.g. { timestamp, knownTests } instead of { timestamp, data }) from
being treated as valid cache hits that return undefined data.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

parts.join('|') is collision-prone: fields containing '|' or undefined
values collapsing with '' can produce identical hashes for different
inputs. JSON.stringify(parts) preserves array structure and
distinguishes undefined from '' and objects from their string form.

Remove redundant JSON.stringify(custom) at call sites since the
top-level JSON.stringify handles it.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Exercise the cached-return path for getSkippableSuites (including
correlationId unwrap) and getTestManagementTests. Each test file
verifies: fetch + callback shape, cache hit on second call, and
lock cleanup.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

…eness

The fixed 2-minute deadline caused waiters to fall back to direct fetch
even when the lock owner was still alive (heartbeat fresh). This
defeated deduplication for slow paginated fetches that exceed 2 minutes.

Now waiters only fall back when isLockStale() returns true (lock file
timestamp older than 2 minutes without heartbeat update), which
correctly distinguishes a crashed owner from a slow healthy one.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

writeFileSync truncates the file before writing, creating a brief
window where the lock file is empty. Waiters polling at that moment
read Number('') = 0, compute Date.now() - 0 > 120000 = true, and
misclassify the lock as stale — breaking deduplication.

Use temp file + rename (same pattern as writeToCache) so readers
always see either the old timestamp or the new one, never empty.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

- mergeKnownTests is only used internally, no need to export
- integration test helpers don't need changes since cache is opt-in

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>