Add --log-markers option to extract Log-type marker payloads

[alastor0325]

Summary

• --top-markers and --focus-marker silently skip zero-duration markers, making about:logging media profiles unanalyzable — the log messages are stored as instant Log-type markers with no duration
• Add --log-markers [filter] which reads these markers directly from profile.threads, extracts data.name / data.module from each type:"Log" entry, and outputs them grouped by thread in chronological order
• An optional filter string restricts output by message text, module name, or thread name (case-insensitive)

What --log-markers is for

When Firefox captures an about:logging profile with the "Media playback" preset, the media pipeline log messages are stored as instant Log-type markers (zero duration, point-in-time). Examples:

[D/MediaDecoder] MediaDecoderStateMachine[...] state=LOOPING_DECODING audio sample after time-adjustment
[V/MediaFormatReader] Update(Video) desc:blank media data decoder pending:0 waiting:0
[V/AudioSinkWrapper] Dropping audio packets: media position: 1565.790710, packet dropped: [1565.760, 1565.781] (1 so far).

These are invisible to --top-markers (which skips markers without an end time) and to --focus-marker (which filters CPU samples, not log text).

Usage

# All log markers across all threads
profiler-cli <url> --log-markers

# Filter by thread name
profiler-cli <url> --log-markers "MediaDecoderStateMachine"

# Filter by message content
profiler-cli <url> --log-markers "blank media"

# Filter by module
profiler-cli <url> --log-markers "D/MediaDecoder"

Implementation notes

• getLogMarkers() in profiler.ts accesses selectors.profile.getProfile(getState()).threads directly — bypassing window.filteredMarkers which only covers the currently selected thread and skips zero-duration entries
• data.name for Log-type markers is already a fully resolved string in the Redux store (no string table lookup needed)
• The markers table uses startTime (not time) as the timestamp field

Tests

• tests/options.test.ts: unit tests for flag parsing and validateArgs
• tests/log-markers.test.ts: integration tests against a new fixture (log-markers-profile.json.gz) — covers all-markers output, module label formatting, message/module/thread filtering, no-match message, chronological sort, and timestamp format

[alastor0325]

@dpalmeiro could you help review this? Thanks!