file: validate output path for OS-specific invalid characters

[twmb]

Override the benthos file output with a connect-local implementation that rejects characters causing silent data loss: colons on macOS (HFS+/APFS maps ':' to '/'), and <, >, :, ", |, ?, * plus control characters on Windows. NUL bytes are rejected on all platforms.

Fixes #1005.

[claude]

Claude finished @twmb's task in 4m 40s —— View job

---

• Setup: fetch PR data and read agent guidelines
• Step 1: Commit policy validation
• Step 2: Code review
• Step 3: Post summary

---

Commits

LGTM

Review

Clean implementation that overrides the benthos file output to add OS-specific path validation. Registration pattern, field name constants, config parsing, mutex usage, and test structure all follow project conventions. One minor pattern violation found.

1. Error wrap prefix at output_file.go#L187 uses "path interpolation error: %w" instead of gerund form ("interpolating path: %w") per godev.md.

---

[claude]

Error wrap prefix should use gerund form per godev.md: "Prefix with the action in gerund form". Change "path interpolation error: %w" to something like "interpolating path: %w".

[claude]

Claude finished @twmb's task in 1m 40s —— View job

---

• Setup: fetch PR data and read agent guidelines
• Step 1: Commit policy validation
• Step 2: Code review
• Step 3: Post summary

---

Commits

LGTM

Review

Reviewed 4 files: new file output override with OS-specific path validation (output_file.go, 336 lines), table-driven tests (output_file_test.go, 159 lines), doc reorder (file.adoc, +2/-2), and public wrapper import (package.go, +3 lines). Component registration, ConfigSpec construction, field name constants, ParsedConfig extraction, error handling, mutex encapsulation, idempotent Close, license headers (2026), and test patterns all follow project conventions.

1. Error wrap prefix at output_file.go#L187 still uses "path interpolation error: %w" instead of gerund form ("interpolating path: %w") per godev.md. (Same issue as previous review.)

---

[mmatczuk]

Reminds me of https://github.com/saucelabs/forwarder/blob/main/fileurl/fileurl.go