feat(chat): Add fsRead tool for Amazon Q Agentic Chat

[tsmithsz]

Problem

Amazon Q Agentic Chat needs the ability to read files and directories from the user's workspace to provide context-aware assistance. Currently, there's no tool available for Amazon Q to access the file system in a controlled and secure manner.

Solution

• Implemented a new fsRead tool that allows Amazon Q to:
• Read entire files or specific line ranges
• List directory contents with configurable depth
• Handle error cases gracefully with informative messages
• Enforce size limits (30KB) to prevent excessive memory usage

Testing

FsRead Unit Tests
extensionHostProcess.js:178
    ✔ reads entire file
extensionHostProcess.js:178
    ✔ reads partial lines of a file
extensionHostProcess.js:178
    ✔ lists directory contents up to depth = 1
extensionHostProcess.js:178
    ✔ throws error if path does not exist
extensionHostProcess.js:178
    ✔ throws error if content exceeds 30KB
extensionHostProcess.js:178
    ✔ invalid line range

---

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• Your code changes must meet the guidelines in CONTRIBUTING.md.
• License: I confirm that my contribution is made under the terms of the Apache 2.0 license.

[github-actions]

• This pull request implements a feat or fix, so it must include a changelog entry (unless the fix is for an unreleased feature). Review the changelog guidelines.
  • Note: beta or "experiment" features that have active users should announce fixes in the changelog.
  • If this is not a feature or fix, use an appropriate type from the title guidelines. For example, telemetry-only changes should use the telemetry type.

[tsmithsz]

/retrybuilds

[tsmithsz]

/retrybuilds

[tsmithsz]

/retrybuilds

[justinmk3]

This should live in fs.ts. Not related to "workspaces".