feat: add response header overrides for downloads

[goanpeca]

Summary

• Adds response-content-disposition, response-content-type, and response-cache-control inputs for presign/download response header overrides.
• Validates override values for control characters, field length, and field-specific syntax before B2 requests.
• Threads validated overrides through B2 download options and presigned URL authorization/query params, with presign authorization centralized behind one helper.
• Documents the new inputs, updates the changelog, and regenerates the bundled dist artifact.

Linked issue

• Closes presign/download: response-header overrides (filename, content-type, cache-control) #95

Tests run

• pnpm test
• pnpm typecheck
• pnpm lint
• pnpm docs:check-action-yml
• pnpm check:release-provenance
• pnpm build
• pnpm spellcheck

Follow-up notes

• None.

[github-actions]

Build artifact for this PR: build.tar.gz (valid 1 hour)

[Copilot]

Pull request overview

This PR adds support for overriding download response headers (Content-Disposition, Content-Type, Cache-Control) via new action inputs, wiring them through both direct downloads and presigned URLs (including the download-authorization request and the resulting URL query params).

Changes:

• Introduces new inputs (content-disposition, response-content-type, cache-control) and parses them into ParsedInputs.
• Threads these overrides into download (SDK bucket.download options) and presign (download authorization + appended query params on the presigned URL).
• Updates documentation, action metadata, tests, and the committed dist/ bundle.

Reviewed changes

Copilot reviewed 10 out of 12 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
src/inputs.ts	Adds parsed inputs for response header overrides.
src/download-overrides.ts	Centralizes mapping from inputs → SDK override options and URL query params.
src/commands/presign.ts	Includes overrides in b2_get_download_authorization and appends them to presigned URLs.
src/commands/download.ts	Passes overrides through to bucket.download() calls.
action.yml	Documents the new inputs on the action surface.
README.md	Documents new inputs and updates the presign download example.
tests/inputs.test.ts	Adds coverage for parsing the new inputs.
tests/commands/upload-download.test.ts	Verifies download calls receive the override options.
tests/commands/delete-copy-presign.test.ts	Verifies presign auth request + URL query params include overrides.
tests/_parsed-inputs.ts	Updates test helper defaults for the expanded ParsedInputs shape.
dist/index.js	Updates bundled output to match the new source behavior.

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[github-actions]

Build artifact for this PR: build.tar.gz (valid 1 hour)

[Copilot]

Pull request overview

Copilot reviewed 11 out of 13 changed files in this pull request and generated no new comments.

[Copilot]

Pull request overview

Copilot reviewed 11 out of 13 changed files in this pull request and generated no new comments.

[github-actions]

Build artifact for this PR: build.tar.gz (valid 1 hour)

[Copilot]

Pull request overview

Copilot reviewed 11 out of 13 changed files in this pull request and generated no new comments.