Remove ai_provider_ref() from ai_list_providers() so the returned
providers do not need to be unref'd by the caller. This matches the
header docstring which states "caller must not free the list or
providers". Also update all callers (cmd_ai_providers, tests) to
remove redundant ai_provider_unref() calls.
Add an AI client module that integrates with OpenAI-compatible API
providers (OpenAI, Perplexity, and custom providers) to provide
AI-assisted responses within the profanity client.
The implementation includes:
- src/ai/ai_client.c/h: Core AI client with provider management,
session handling, and async HTTP request handling via libcurl.
Supports per-provider API keys stored in preferences, reference-
counted sessions, and conversation history tracking.
- src/ui/window.c/window_list.c: New AI window type (ProfAiWin) for
displaying AI conversations, with response streaming and error
display capabilities.
- Command integration: New `/ai` command (cmd_defs.c, cmd_funcs.c)
for creating sessions, sending prompts, and managing providers.
Provider autocomplete support in cmd_ac.c.
- Preferences integration: API keys for providers are persisted in
the preferences system (config/preferences.c).
- Unit tests: 472 lines of comprehensive tests covering provider
management, session lifecycle, JSON escaping, and autocomplete
(tests/unittests/test_ai_client.c).
Architecture decisions:
- Asynchronous design: HTTP requests run on a separate thread to
avoid blocking the main UI loop. Callbacks are invoked on the main
thread via direct function call (profanity uses ncurses, not GLib
main loop).
- Reference counting: Both AIProvider and AISession use ref counting
for safe shared ownership.
- Response size limit: 10MB cap on HTTP responses to prevent OOM.
