[gandazgul]

Converts active-agent switching to TypeScript without changing switch transactions, root or handler reuse, manual model inheritance, transition completion, workflow release, or turn dispatch. Named switch/turn options, results, and metadata stay with the implementation. Turn options reuse shared switch fields and native SDK, Session, image, MCP, and managed-operation types. Updates all 15 consumers, the architecture allowlist, three live references, and the JavaScript baseline.

No any, unknown, or type assertions are added. Runtime expressions, errors, lifecycle calls, and test assertions remain unchanged.

Validation:

• Frozen root/docs installation with Bun 1.4.3; initialized submodules are clean.
• All 11 preliminary CI checks pass, including type checks, lint, language policy, documentation links, and Workspace build.
• All 175 existing focused cases pass: 17 agent-switching, 22 architecture-boundary, 103 SessionRuntime, and 33 Agy execution cases. No cases added or removed.
• Emitted runtime JavaScript AST matches the original module exactly; all 15 consumers match apart from native extension references.
• Independent Standards, Spec, and Tests reviews are clear.
• Full GitHub source and Golden CI required before merge.