### Breaking Changes
- `before_agent_start` event now receives `systemPrompt` in the event object and returns `systemPrompt` (full replacement) instead of `systemPromptAppend`. Extensions that were appending must now use `event.systemPrompt + extra` pattern. ([#575](https://github.com/badlogic/pi-mono/issues/575))
- `discoverSkills()` now returns `{ skills: Skill[], warnings: SkillWarning[] }` instead of `Skill[]`. This allows callers to handle skill loading warnings. ([#577](https://github.com/badlogic/pi-mono/pull/577) by [@cv](https://github.com/cv))
### Added
- `ctx.ui.getAllThemes()`, `ctx.ui.getTheme(name)`, and `ctx.ui.setTheme(name | Theme)` methods for extensions to list, load, and switch themes at runtime ([#576](https://github.com/badlogic/pi-mono/pull/576))
- `--no-tools` flag to disable all built-in tools, allowing extension-only tool setups ([#557](https://github.com/badlogic/pi-mono/pull/557) by [@cv](https://github.com/cv))
- Pluggable operations for built-in tools enabling remote execution via SSH or other transports ([#564](https://github.com/badlogic/pi-mono/issues/564)). Interfaces: `ReadOperations`, `WriteOperations`, `EditOperations`, `BashOperations`, `LsOperations`, `GrepOperations`, `FindOperations`
- `user_bash` event for intercepting user `!`/`!!` commands, allowing extensions to redirect to remote systems ([#528](https://github.com/badlogic/pi-mono/issues/528))
- `setActiveTools()` in ExtensionAPI for dynamic tool management
- Built-in renderers used automatically for tool overrides without custom `renderCall`/`renderResult`
- `ssh.ts` example: remote tool execution via `--ssh user@host:/path`
- `interactive-shell.ts` example: run interactive commands (vim, git rebase, htop) with full terminal access via `!i` prefix or auto-detection
- Wayland clipboard support for `/copy` command using wl-copy with xclip/xsel fallback ([#570](https://github.com/badlogic/pi-mono/pull/570) by [@OgulcanCelik](https://github.com/OgulcanCelik))
- **Experimental:** `ctx.ui.custom()` now accepts `{ overlay: true }` option for floating modal components that composite over existing content without clearing the screen ([#558](https://github.com/badlogic/pi-mono/pull/558) by [@nicobailon](https://github.com/nicobailon))
- `AgentSession.skills` and `AgentSession.skillWarnings` properties to access loaded skills without rediscovery ([#577](https://github.com/badlogic/pi-mono/pull/577) by [@cv](https://github.com/cv))
### Fixed
- String `systemPrompt` in `createAgentSession()` now works as a full replacement instead of having context files and skills appended, matching documented behavior ([#543](https://github.com/badlogic/pi-mono/issues/543))
- Update notification for bun binary installs now shows release download URL instead of npm command ([#567](https://github.com/badlogic/pi-mono/pull/567) by [@ferologics](https://github.com/ferologics))
- ESC key now works during "Working..." state after auto-retry ([#568](https://github.com/badlogic/pi-mono/pull/568) by [@tmustier](https://github.com/tmustier))
- Abort messages now show correct retry attempt count (e.g., "Aborted after 2 retry attempts") ([#568](https://github.com/badlogic/pi-mono/pull/568) by [@tmustier](https://github.com/tmustier))
- Fixed Antigravity provider returning 429 errors despite available quota ([#571](https://github.com/badlogic/pi-mono/pull/571) by [@ben-vargas](https://github.com/ben-vargas))
- Fixed malformed thinking text in Gemini/Antigravity responses where thinking content appeared as regular text or vice versa. Cross-model conversations now properly convert thinking blocks to plain text. ([#561](https://github.com/badlogic/pi-mono/issues/561))
- `--no-skills` flag now correctly prevents skills from loading in interactive mode ([#577](https://github.com/badlogic/pi-mono/pull/577) by [@cv](https://github.com/cv))