fix(runtime): return the newest worker window from getApplicationLastProfile

[mcollina]

Problem

Same family as #5022, different method: getApplicationLastProfile resolved a bare application id through the round-robin worker selector. With multiple workers, the live pull could land on a worker whose continuous profiler was never started, fail with PLT_PPROF_PROFILING_NOT_STARTED, find no preserved overload profile, and throw — intermittently, depending on where the rotor pointed. Even when it didn't fail, it could return an arbitrary worker's window instead of the application's most recent one.

Fix

There was already an asymmetry pointing at the right semantics: the preserved-overload-profile fallback (#getPreservedOverloadProfile) treats a bare application id as "scan all workers, return the newest", while the live path picked one arbitrary worker.

The live path now matches: for an application-level id, getLastProfile is pulled from every worker in parallel (new #pullLastProfiles helper), inside the existing single options.timeout budget, and the newest window wins.

• Explicit application:workerIndex ids keep the current single-worker behavior.
• Per-worker failures with codes in the fallback set (PROFILING_NOT_STARTED, NO_PROFILE_AVAILABLE, …) are ignored as long as at least one worker yields a profile; if all fail, the first error flows into the existing preserved-profile fallback exactly as before. Non-fallback errors still rethrow immediately.
• The preserved-entry pruning (a strictly newer live window supersedes the preserved copy) now runs per responding worker.
• Results without a timestamp (older capture modules) lose to timestamped ones when picking the newest.

This is independent of #5022 (which fixes start/stop pairing): here no pinning is needed because all workers are queried.

Testing

TDD from main: packages/runtime/test/get-last-profile-workers.test.js (new, 4 tests on a 2-worker fixture). The first test reproduced the reported intermittent failure before the fix (consecutive bare-id calls, one of which rotated onto the unprofiled worker) and passes after; the second asserts the newest-across-workers semantics.

• new suite: 4/4
• packages/runtime/test/extensions.test.js: 19/19
• packages/wattpm-pprof-capture/test/watt-pprof-capture.test.js (covers preserved/overload/blocked-worker paths of this method): 36/36
• lint clean

🤖 Generated with Claude Code

[ShogunPanda]

LGTM!