Add file policy to prevent sensitive file leak

[jeffreyflynt]

[1.0.25]

Added

• .tenure.json configuration format (tenureConfig.ts): Introduced a new JSON-based project configuration file supporting projectId, ignore, and noiseIgnores fields alongside the legacy plain-text .tenure file. The JSON format is preferred when both files exist, with automatic fallback to .tenure.
• generateDefaultTenureConfig() (tenureConfig.ts): Added a utility function that produces a pretty-printed .tenure.json template with empty ignore and noiseIgnores arrays, used when prompting users to create a new config file.
• File policy module (filePolicy.ts): Added getTenureFilePolicy() and getTenureFilePolicyForPath() to support per-file metadata and content suppression rules, preventing sensitive files from leaking active file paths, language IDs, edit events, or content to the Tenure proxy.
• .tenure.json file watcher (extension.ts): Added a dedicated filesystem watcher for .tenure.json changes that invalidates the sync cache and triggers a re-sync, alongside the existing .tenure watcher.

Changed

• Version and display name (package.json, package-lock.json): Bumped extension version to 1.0.25, updated the display name to "Tenure", added language-models to keywords, set "type": "module", and added bugs and homepage fields.
• Build configuration (package.json, tsdown.config.ts): Replaced the separate build:test npm script with a unified tsdown config that handles both extension and test builds. The test command now references .vscode-test.cjs instead of the removed .vscode-test.js.
• Onboarding prompt wording (workspaceSync.ts): Updated the missing config file prompt to reference .tenure.json instead of .tenure, now creating a JSON document with generateDefaultTenureConfig() rather than a plain-text file.
• File metadata suppression in workspace sync (workspaceSync.ts): Integrated file policy checks into buildWorkspaceState() and sendActiveFileUpdate() so that files matching suppression rules omit their path and language from workspace state payloads.
• File metadata suppression in beliefs provider (beliefsViewProvider.ts): Added file policy checks to sendFileMeta(), sendFileEdited(), and the belief record submission flow, suppressing metadata and content for files covered by suppression rules.
• Active editor change handling (extension.ts): Updated the onDidChangeActiveTextEditor handler to respect file policy suppression, skipping active file propagation for suppressed files.
• README update (README.md): Revised the project description, feature descriptions, and drift explanation to emphasize Tenure as a governed context layer rather than just persistent memory.

Removed

• .vscode-test.js (integrations/vscode/.vscode-test.js): Deleted the legacy test runner configuration file, replaced by .vscode-test.cjs.
• Unused @emnapi/core and @emnapi/runtime packages (package-lock.json): Removed these optional dependencies from the lockfile.
• Redundant platform metadata (package-lock.json): Stripped libc annotations from optional native dependency entries (@emnapi/wasi-threads platform variants).