feat(profiling): Add Perfetto trace format support

[markushi]

This PR adds the ability to ingest binary Perfetto traces (.pftrace) and convert them into the existing Sample v2 JSON format used by Sentry's profiling pipeline. This targets Android
profiling, where Perfetto is the native tracing format.

Key Changes

1. New feature flag organizations:continuous-profiling-perfetto — gates all Perfetto processing.
2. Compound item format via meta_length — profile chunk items can now carry [JSON metadata][binary blob], split at meta_length. This is how Perfetto traces arrive: metadata describes the
   profile, the binary blob is the raw .pftrace.
3. Perfetto → Sample v2 conversion — new relay-profiling/src/perfetto/ module (proto definitions + conversion logic) parses binary Perfetto traces and produces the existing Sample v2
   JSON format.
4. Raw profile passthrough to Kafka — after expansion, the original Perfetto binary is preserved alongside the expanded JSON. Two new fields on ProfileChunkKafkaMessage: raw_profile and
   raw_profile_content_type.
5. New fields on existing structs:
   - Frame.package — library/container path for native/Java frames
   - ProfileMetadata.content_type — carries "perfetto" through the pipeline
   - DebugImage::native_image() constructor — creates debug images from Perfetto mapping data

[markushi]

@sentry review

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

Autofix Details

Bugbot Autofix prepared a fix for the issue found in the latest run.

• ✅ Fixed: First timestamp delta skipped in StreamingProfilePacket processing
  • Removed the 'i > 0' guard so that timestamp_delta_us[0] is now correctly applied to the first sample's timestamp.

Or push these changes by commenting:

@cursor push ab5f3ec796

Preview (ab5f3ec796)

diff --git a/relay-profiling/src/perfetto/mod.rs b/relay-profiling/src/perfetto/mod.rs
--- a/relay-profiling/src/perfetto/mod.rs
+++ b/relay-profiling/src/perfetto/mod.rs
@@ -229,9 +229,7 @@
             Some(Data::StreamingProfilePacket(spp)) => {
                 let mut ts = packet.timestamp.unwrap_or(0);
                 for (i, &cs_iid) in spp.callstack_iid.iter().enumerate() {
-                    if i > 0
-                        && let Some(&delta) = spp.timestamp_delta_us.get(i)
-                    {
+                    if let Some(&delta) = spp.timestamp_delta_us.get(i) {
                         // `delta` is i64 (can be negative for out-of-order samples).
                         // Casting to u64 wraps negative values, which is correct because
                         // `wrapping_add` of a wrapped negative value subtracts as expected.

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[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

^{Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.}

[cursor]

Streaming profile samples all assigned thread ID zero

Medium Severity

All StreamingProfilePacket samples are pushed with tid = 0, losing the actual thread identity. Perfetto associates each StreamingProfilePacket with a thread via the trusted_packet_sequence_id → TrackDescriptor → ThreadDescriptor chain, but this code never resolves that mapping. Every streaming sample ends up with thread_id: "0", which collapses multi-thread profiles into one thread and produces incorrect output for the profiling UI.