- Standardized missing-file read errors and now return `File not found: <path>` for absent edit targets.
- Centralized AI provider, usage, and OAuth helpers into shared modules to remove duplicated logic.
- Migrated OAuth/API-key login flows to shared factory helpers and removed inline prompt/token-exchange code.
- Reused shared tools and formatter utilities for discovery, stream tails, LSP batching, and source formatting.
- Consolidated repeated test helpers and fixtures into shared modules, replacing inline helper duplicates.
- Extracted OpenAI compatibility detection and resolution logic into dedicated `openai-completions-compat` module.
- Refactored `detectCompat()` and `getCompat()` to delegate to new compat module functions with simplified conditional logic.
- Fixed OAuth redirect URI validation to preserve exact configured values without trailing slash normalization.
- Improved session deletion to return boolean status and display error messages in UI instead of silently failing.
- Added `/session delete` command with Delete key support and confirmation dialogs for session management.
- Extracted fetch mocking logic into reusable `hookFetch()` utility function with middleware-style handler pattern.
- Replaced manual `globalThis.fetch` assignment and restoration across 10 test files with `hookFetch()` calls using `using` statement for automatic cleanup.
- Implemented Disposable pattern with Symbol.dispose for fetch hook resource management, eliminating try-finally blocks.
- Exported `hookFetch` from utils public API to enable consistent fetch mocking across packages.
- Updated OAuth client name from 'oh-my-pi MCP' to 'Codex' for dynamic client registration.
- Added test coverage for OAuth client registration with Codex identity.