fix(acp): preserve file source location when converting text resource blocks

[adityachaudhary99]

Issue for this PR

Closes#32558

Type of change

• Bug fix

What does this PR do?

When an ACP client (e.g. Zed) attaches a selected snippet as a resource content block with inline text, opencode was silently dropping the resource's uri. The snippet arrived as a bare text part with no provenance — the LLM and session replays had no way to trace it back to its source file or line range.

This PR adds a fileSourcePrefix helper that, when a text resource block carries a file:// uri, prefixes the text with the resolved file path (and line range when the uri contains a #L12 or #L12-15 fragment):

[/abs/path/to/app.ts:12-15]
const x = 1

Non-file:// uris (e.g. https://) and unparseable uris fall through unchanged — the helper returns undefined and the original text passes through untouched.

The Chat Completions (/resource_link) path is left unchanged.

How did you verify your code works?

Added three focused unit tests to packages/opencode/test/acp/content.test.ts:

• "resource with text prefixes the file source location" — verifies the file path prefix is prepended
• "resource with text includes the line range from the uri fragment" — verifies #L12-15 fragment parses to :12-15 in the prefix
• "resource with text and a non-file uri is left untouched" — verifies https:// uris pass through unchanged

Test URIs are constructed via path.resolve + pathToFileURL so they round-trip correctly on all platforms (Windows and POSIX). All 15 tests in the content suite pass.

Screenshots / recordings

N/A — no UI change.

Checklist

• I have tested my changes locally
• I have not included unrelated changes in this PR

[github-actions]

Thanks for updating your PR! It now meets our contributing guidelines. 👍

[github-actions]

Automated PR Cleanup

Thank you for contributing to opencode.

Due to the high volume of PRs from users and AI agents, we periodically close older PRs using automated criteria so maintainers can focus review time on the most active and community-supported contributions.

This PR was closed because it matched the following cleanup criteria:

• The PR was created more than 1 month ago
• The PR had fewer than 2 positive reactions
• Positive reactions are counted as thumbs-up, heart, celebration, or rocket reactions on the PR

PRs created within the last month are not affected by this cleanup.

If you believe this PR was closed incorrectly, or if you are still actively working on it, please leave a comment explaining why it should be reopened. A maintainer can review and reopen it if appropriate.

Thanks again for taking the time to contribute.