feat(files): add file management commands

[casey-brooks]

Summary

• add files command group (upload/download/info/url) with streaming support
• infer content types, resolve download paths, and format file metadata outputs
• update buf generation inputs and include files protos/codegen updates
• add unit tests for content type inference, download path resolution, and expiry parsing
• extend command smoke test coverage for files
• note: files download accepts optional positional [destination] to avoid clashing with global --output/-o format flag

Testing

• go vet ./...
• go test ./...
• bash scripts/command_smoke_test.sh

Fixes #23

[casey-brooks]

Test & Lint Summary

• go vet ./... (no issues)
• go test ./... (passed: all, failed: 0, skipped: 0)
• bash scripts/command_smoke_test.sh (passed: all, failed: 0, skipped: 0)

[noa-lucent]

Clean, well-structured implementation that follows the existing codebase patterns closely. The file organization, output handling, streaming logic, and error handling are all solid and consistent with the expose/threads commands.

Two minor items flagged:

1. parseExpiryDuration should reject non-positive durations (negative/zero) — straightforward boundary validation gap.
2. TestFileOutputFrom should assert all mapped fields, not just ID and Filename.

Overall the PR meets the acceptance criteria from #23: all four subcommands are implemented per spec, proto codegen is updated, tests cover the pure functions, and smoke tests are extended. Nice work.

[casey-brooks]

Test & Lint Summary

• go vet ./... (no issues)
• go test ./... (passed: all, failed: 0, skipped: 0)
• bash scripts/command_smoke_test.sh (passed: all, failed: 0, skipped: 0)

[noa-lucent]

Both prior comments addressed correctly:

1. parseExpiryDuration now rejects non-positive durations with test coverage for "0s" and "-1h".
2. TestFileOutputFrom now asserts ContentType and SizeBytes.

All threads resolved. LGTM.

[casey-brooks]

Updated files download to accept an optional positional destination and removed the --output-path flag. Smoke test and resolveDownloadPath tests updated accordingly.

Test & Lint Summary

• go vet ./... (no issues)
• go test ./... (passed: all, failed: 0, skipped: 0)
• bash scripts/command_smoke_test.sh (passed: all, failed: 0, skipped: 0)

[noa-lucent]

Good simplification. Replacing --output-path with a positional [destination] argument is a cleaner UX that neatly avoids the --output naming collision. The code is simpler (no args struct, no flag registration), the test coverage is extended with the whitespace-trim case, and resolveDownloadPath continues to handle the empty-destination fallback correctly.

One nit on the stale PR description — no code issues.

[casey-brooks]

Removed tracked generated sources under gen/ and updated release workflow to install Buf + run buf generate before building binaries.

Test & Lint Summary

• buf generate
• go vet ./... (no issues)
• go test ./... (passed: all, failed: 0, skipped: 0)
• bash scripts/command_smoke_test.sh (passed: all, failed: 0, skipped: 0)

[casey-brooks]

Rebased on main to resolve the gen/ delete vs. modify conflict, keeping generated sources removed. CI has restarted (build job pending).

Test & Lint Summary

• buf generate
• go vet ./... (no issues)
• go test ./... (passed: all, failed: 0, skipped: 0)
• bash scripts/command_smoke_test.sh (passed: all, failed: 0, skipped: 0)

[noa-lucent]

Rebase and restructuring look clean. Reviewing the new changes:

Dropping committed gen/ sources: Good housekeeping. gen/ is properly gitignored, the Dockerfile's generate stage runs buf generate, and the release workflow's binary job now includes the Buf setup + generate steps. The image job correctly relies on the Dockerfile multi-stage build for codegen — no gap.

Threads refactor (threads.go + threads_test.go): The migration from splitParticipants (two-pass: create with IDs, then separately add nicknames) to participantIdentifiersFromValues (single-pass using the updated CreateThreadRequest.Participants field) is a clear improvement. Dedup uses a seen map instead of the old O(n²) appendUnique helper. The --organization-id flag is correctly wired as an optional proto field (*string). Dead code (appendUnique, splitParticipants) is fully removed. Tests updated with proper type assertions on the ParticipantIdentifier oneof variants.

Files command code: Unchanged from last approval — no regressions.

All prior threads resolved. LGTM.