fix - file and directory link navigation in chat tool results

[xinyi-gong]

Fixes #262

Problem

Clicking file path links in Chat tool results fails to open files that are outside the Eclipse workspace. Directory links in the workspace also had no meaningful behavior.

Changes

• When a file link does not resolve to a workspace resource, fall back to opening it as a local filesystem file in an editor.
• Handle workspace directory and project links by revealing them in the Project Explorer instead of opening the browser.
• Centralized local path resolution logic into the core bundle, removing duplication from the file tools.

[Copilot]

Pull request overview

This PR fixes chat tool result link navigation by improving how file and directory hyperlinks are resolved and opened in the Eclipse UI, especially for local filesystem paths outside the workspace.

Changes:

• Centralizes local filesystem path/file: URI parsing in core via FileUtils.getLocalFilePath(...) and updates file tools to use it.
• Updates chat hyperlink opening to:
  • open local files outside the workspace in an editor, and
  • reveal workspace folders/projects in Project Explorer (instead of delegating to the browser).
• Extends SWTBot test plan documentation with a new test case covering local file link navigation.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
com.microsoft.copilot.eclipse.ui/src/com/microsoft/copilot/eclipse/ui/chat/tools/FileToolBase.java	Removes duplicated local-path parsing helper (now centralized in core).
com.microsoft.copilot.eclipse.ui/src/com/microsoft/copilot/eclipse/ui/chat/tools/EditFileTool.java	Switches to FileUtils.getLocalFilePath(...) for local edits.
com.microsoft.copilot.eclipse.ui/src/com/microsoft/copilot/eclipse/ui/chat/tools/CreateFileTool.java	Switches to FileUtils.getLocalFilePath(...) for local creates.
com.microsoft.copilot.eclipse.ui/src/com/microsoft/copilot/eclipse/ui/chat/FileAnnotationHyperlinkDetector.java	Adds folder/project reveal + local-file editor fallback for file: links.
com.microsoft.copilot.eclipse.swtbot.test/test-plans/file-system/local-file-edit-and-create-tools.md	Adds a test plan section for navigating to local files from tool links.
com.microsoft.copilot.eclipse.core/src/com/microsoft/copilot/eclipse/core/utils/FileUtils.java	Adds getLocalFilePath(...) and fragment stripping to support consistent parsing.