agentivity_ag_ui

chore: bump version to 0.3.12

Release 0.3.12

Clean versioning release — correct tag/pubspec alignment.

• Re-tagged release to ensure the published version on pub.dev matches the Git tag and pubspec version.
• No functional changes since 0.3.5.

Generative UI, protocol alignment, state sync, and frontend tools.

New capabilities

• Generative UI — AgUiGenerativeController processes Stream<AgUiEvent> and maintains a sealed AgUiGenerativeItem list (AgUiTextItem, AgUiReasoningItem, AgUiComponentItem, AgUiToolCallItem). AgUiGenerativeView renders it reactively with streaming indicators, collapsible reasoning blocks, and tool-call status cards.
• Widget registry — AgUiWidgetRegistry maps component names to Flutter widget builders. The agent calls a tool whose name matches a registered component → the controller seamlessly replaces the placeholder with the live widget. Also supported via CUSTOM events with name == 'render'.
• Frontend tools — AgUiFrontendToolRegistry / AgUiFrontendTool let the agent call client-side code (no backend round-trip). Results are shown inline. Use toApiDescriptions() to include frontend tools in the agent's tool list.
• State sync — AgUiStateController applies STATE_SNAPSHOT and STATE_DELTA (RFC 6902 JSON Patch: add, remove, replace, move, copy) to a reactive state map. AgUiStateBuilder provides a ListenableBuilder wrapper.

Protocol alignment (breaking if you used internal names)

• ToolCallStartEvent: JSON key changed from toolName → toolCallName (legacy toolName still read as fallback).
• ToolCallArgsDeltaEvent: now handles both spec name TOOL_CALL_ARGS and legacy TOOL_CALL_ARGS_DELTA.
• ToolCallResultEvent: field renamed result → content (legacy result read as fallback); messageId is now a required String.
• RunStartedEvent: added threadId, parentRunId.
• RunFinishedEvent: added threadId, outcome (AgUiSuccessOutcome or AgUiInterruptOutcome with List<AgUiInterrupt>). isInterrupted convenience getter.
• Added event types: TextMessageChunkEvent, ToolCallChunkEvent, ReasoningMessageStartEvent, ReasoningMessageContentEvent, ReasoningMessageEndEvent, ReasoningStartEvent, ReasoningEndEvent, ActivitySnapshotEvent, ActivityDeltaEvent, RawEvent.
• StateDeltaEvent.delta is now typed List<dynamic> (RFC 6902 patch array).

Tests

• 150 unit tests covering protocol parsing, JSON Patch operations (including ~0/~1 escaping and - array append), generative controller event handling, and controller notification behaviour.