[0.3.0] — 2026年06月05日

Implements AHP 0.3.0.

Added

• McpServerCustomization now exposes the full MCP lifecycle: enabled,
  the discriminated McpServerState enum
  (.starting/.ready/.authRequired/.error/.stopped), optional
  channel URI for the mcp:// side-channel, and optional mcpApp
  block carrying AhpMcpUiHostCapabilities for MCP Apps.
• McpServerAuthRequiredState carries ProtectedResourceMetadata
  plus reason / requiredScopes / description so the existing
  authenticate command can drive per-server auth.
• Customization.mcpServer top-level case — hosts MAY surface bare
  MCP servers directly rather than only inside a plugin or directory.
• SessionMcpServerStateChangedAction and matching reducer arm —
  narrow upsert of state + channel on an existing MCP
  server customization by id. Wired through both Reducers.swift and
  the protocol-based NativeReducer.swift.
• ClientCapabilities struct on InitializeParams.capabilities with
  first entry mcpApps.
• changeKind field on Changeset (well-known values: 'session',
  'branch', 'uncommitted', 'turn', 'compare-turns').
• status and error fields on ChangesetOperation and the
  changeset/operationStatusChanged action, tracking the
  idle → running → error lifecycle of a changeset operation.
• AgentCustomization._meta provider metadata field.
• Optional changes field on SessionSummary (ChangesSummary with optional additions, deletions, and files counts) summarising a session's file-change footprint.

Changed

• Renamed the ChangesetSummary type to Changeset. The on-the-wire shape is unchanged.
• Moved the changesets catalogue from SessionSummary to SessionState. The session/changesetsChanged action now updates state.changesets directly instead of state.summary.changesets.

Removed

• Removed the additions, deletions, and files fields from ChangesetSummary. Aggregate counts now live on SessionSummary.changes; per-changeset views derive their own totals from ChangesetState.files.

Changed

• ToolCallBase.toolClientId: String? replaced by
  ToolCallBase.contributor: ToolCallContributor? (enum with
  .client(ToolCallClientContributor) and .mcp(ToolCallMcpContributor)
  cases). SessionToolCallStartAction carries the new contributor
  field as well. Reducers.swift, NativeReducer.swift, and
  ToolCallStateExtensions.swift follow the rename.