Balanced fix for snippet Tab conflict (Issue #58)

[albertromkes]

Summary\n\nThis PR introduces a balanced fix for the snippet-mode Tab conflict reported in #58, while preserving existing TabOut behavior for users who prefer it.\n\n### What changed\n\n- Added new setting: \n - (default):\n - In snippet mode, try native snippet placeholder navigation first ().\n - If snippet navigation does not move the cursor, TabOut behavior applies as fallback.\n - :\n - Always prioritize existing TabOut behavior, including in snippet mode.\n\n- Updated command implementation to support the behavior above.\n- Added/updated keybinding config tests to cover the new setting and enum values.\n\n## Why this is balanced\n\n- Fixes #58 by default: snippet placeholder flow is respected.\n- Avoids degrading existing workflows: users who rely on TabOut-first behavior in snippets can switch to .\n- Non-snippet behavior is unchanged.\n\n## Validation\n\n- TypeScript compile:

TabOut@0.2.4 vscode:prepublish
tsc -p ./\n- Existing keybinding guard tests updated for new setting metadata.\n\nCloses #58

[albertromkes]

Summary

This PR introduces a balanced fix for the snippet-mode Tab conflict reported in #58, while preserving existing TabOut behavior for users who prefer it.

What changed

• Added new setting: tabout.snippetTabBehavior

  • preferSnippetNavigation (default):
    • In snippet mode, try native snippet placeholder navigation first (jumpToNextSnippetPlaceholder).
    • If snippet navigation does not move the cursor, TabOut behavior applies as fallback.
  • preferTabOut:
    • Always prioritize existing TabOut behavior, including in snippet mode.

• Updated tabout command implementation to support the behavior above.

• Added/updated keybinding config tests to cover the new setting and enum values.

Why this is balanced

• Fixes Bug: Conflict in the code snippet/在代码片段中冲突 #58 by default: snippet placeholder flow is respected.
• Avoids degrading existing workflows: users who rely on TabOut-first behavior in snippets can switch to preferTabOut.
• Non-snippet behavior is unchanged.

Validation

• TypeScript compile: npm run vscode:prepublish
• Existing keybinding guard tests updated for new setting metadata.

Closes #58