feat(bloat): default output dir + path printing; build --bloat alias

[zackees]

Summary

Closes#439 (Phase 3 of #434). Stacked on top of #443 → #436. Merge those first.

Three pieces of behaviour:

1. Default output dir. When neither --json nor --output-dir is given, fbuild bloat writes both report.json and report.md to <project>/.fbuild/build/<env>/bloat-report/. Project + env come from the build_info.json that fbuild symbols: ingest toolchain paths from build_info.json + extend schema with nm/c++filt/readelf/objdump #428 wired up. When no build_info.json is found, falls back to <elf-parent>/bloat-report/.

2. Path printing on exit. Always closes with a Bloat report: header showing flash/ram totals, then two absolute paths verbatim — one per line:

   Bloat report:
   Flash: 388,380 B across 3,685 symbols
   RAM: 37,460 B across 906 symbols
   Written to:
   /abs/.fbuild/build/esp32s3/bloat-report/report.json
   /abs/.fbuild/build/esp32s3/bloat-report/report.md
   

   Downstream tools can grep -E "report\.(json|md)" to pick the paths up.

3. fbuild build --bloat. Adds a long-form clap alias to the existing --symbol-analysis flag — canonical name is now --bloat, legacy spelling stays accepted as hidden alias.

The internal field name (symbol_analysis) is unchanged to keep churn out of fbuild-cli internals + the MCP wiring — that's a follow-up if we want it.

Test plan

• soldr cargo check -p fbuild-cli --all-targets ✅
• soldr cargo clippy -p fbuild-cli --all-targets -- -D warnings ✅
• soldr cargo test -p fbuild-cli --bin fbuild — 32 passed (was 27 + 5 new)

New tests:

• default_output_dir_uses_project_layout — pin the .fbuild/build/<env>/bloat-report/ shape
• default_output_dir_falls_back_to_elf_parent — bare-ELF fallback
• resolve_returns_project_context_when_build_info_present — ToolPaths::resolve surfaces the ProjectContext
• build_bloat_flag_is_accepted — fbuild build --bloat . parses
• build_symbol_analysis_alias_still_accepted — back-compat alias still parses

🤖 Generated with Claude Code

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on base/target branches other than the default branch.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: ffbcba7f-d21c-4db9-9e54-0ee5d4b39f26

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch feat/issue-439-default-output

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}