feat: report process comm + gpu ID directly from the ebpf

[luytan]

Description

Please include a summary of the changes and if applicable, a related issue.

If this PR introduce a new feature, explain your motivations

Fixes #150 #149

TODO

• Copy-Paste this line

Checklist:

• My code follows the style guidelines of this project (cargo fmt)
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the mdBook documentation
• My changes generate no new warnings (clippy/clang)
• New and existing unit tests pass locally with my changes (either use nix flake check or wait for the ci)

[coderabbitai]

📝 Walkthrough

Summary by CodeRabbit

• Improvements
  • GPU activity reports now include the specific GPU and application name.
  • Process reporting is more accurate by focusing fallback details on currently running applications.
  • Improved handling of process and application identities makes diagnostic information clearer.
• Bug Fixes
  • Malformed activity reports are now detected and logged as warnings instead of being processed silently.
• Tests
  • Added coverage for GPU identification, application-name decoding, report formatting, and process availability checks.

Walkthrough

Changes

GPU-aware report events

Layer / File(s)	Summary
Event contract and eBPF producers crates/cardwire-ebpf/src/maps.rs, crates/cardwire-ebpf/src/helpers.rs	ReportEvent now carries PID, GPU ID, and a 16-byte command name. eBPF reporting paths populate these fields.
Daemon processing and validation crates/cardwire-daemon/src/analyzer/models.rs	The daemon decodes command names, preserves GPU identity, checks process liveness for fallback reporting, logs malformed events, and tests the 24-byte layout.
Map key and helper updates crates/cardwire-ebpf/src/helpers.rs, crates/cardwire-ebpf/src/main.rs	Map operations now use scalar keys directly. Helper lookups preserve their existing fallback behavior.

Estimated code review effort: 3 (Moderate) | ~25 minutes

Possibly related PRs

• OpenGamingCollective/cardwire#116: Shares ReportEvent, GPU processing, and eBPF per-process GPU-selection changes.
• OpenGamingCollective/cardwire#137: Introduced related Rust/aya-ebpf ReportEvent handling.
• OpenGamingCollective/cardwire#147: Modifies related process identity and GPU fields in daemon report handling.

🚥 Pre-merge checks | ✅ 3 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Description check	⚠️ Warning	The description retains the template but does not include a change summary, motivation, or completed checklist items.	Add a specific summary and motivation, replace the TODO placeholder, and complete the checklist with accurate project status.

✅ Passed checks (3 passed)

Check name	Status	Explanation
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Title check	✅ Passed	The title clearly and concisely describes the main change: direct eBPF reporting of process command names and GPU IDs.

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