What Problem This Solves

Internal implementation types were still exported across core, Control UI, and bundled plugins even though no repository consumer imports them. Those exports enlarge module surfaces and keep appearing in dead-code reports.

Why This Change Was Made

The fresh codebase-memory graph and exact-head ts-unused-exports report agreed on 12 file-local type aliases. Repository-wide reference checks confirmed each symbol is used only by its defining module and is not re-exported through a public barrel or plugin API.

This localizes:

• 4 core agent types
• 4 Control UI types
• 4 bundled plugin types

Runtime implementations and exported functions are unchanged.

User Impact

No user-visible behavior changes. The internal API surface is smaller and the dead-code signal is less noisy.

Evidence

• Fresh full, non-shallow worktree from origin/main
• codebase-memory MCP index: 20,910 files, 276,935 nodes, 1,111,784 edges
• graph query: all 12 selected types had zero in-degree/out-degree and were not entry points
• exact Testbox dead-code report: 3,685 lines before, 3,669 after; all 12 selected symbols absent
• Testbox tbx_01kwwzqg6e2sz1qbbebcya65mt: 6 Vitest shards, 8 focused files, 142 tests passed
• Testbox check:changed: core, core tests, extensions, and extension tests lanes passed
• git diff --check
• fresh Codex autoreview: clean, no accepted/actionable findings, 0.87 confidence