[agentydragon]

Move the sampler's remaining resident scheduling, Code Mode binding, provider I/O and turn/drain orchestration into internal/residentruntime, with its tests. The command composes concrete owners; RPC keeps its concrete Runtime pointer. No Go implementation or forwarding package remains at the service root.

All 25 moved Go files differ only in their package declaration and the primary constructor name (residentruntime.New). Lease claim/renew/release, permits, wakeup reconciliation, provider retries, interrupts, effect settlement and shutdown order are unchanged. SQL and migrations remain Store-owned; Runner transport/effects remain Executor-owned; admission and streaming remain RPC-owned.

Update every import, BUILD target, active source reference and verification instruction together. Test registration retains race mode and real PostgreSQL/host fixtures. Parent review confirms all 141 production SQL literals and all 290 existing sampler test functions remain, and every tracked sampler test file belongs to a go_test.

Validation: command service image builds on RBE; formatting, Gazelle and commit hooks pass. All four resident-runtime and RPC unit/integration suites pass on the combined Store/RPC/Executor tree; hosted CI checks the published head separately.

• Service image: https://www.buildbuddy.io/invocation/76b75277-45b5-4fa1-b4a5-bc48a6f5044f
• Behavioral suites (passed): https://www.buildbuddy.io/invocation/d954c215-8bdb-4ee5-9238-2a6127ac7350
• Review commit: 80ebb5325f.

Proposed, ready successor to #16230 in native stack #16208. This completes the four sampler ownership extractions after its content/migration leaves. Lifecycle redesign, privileged-backend authentication standardization and protobuf wire-name/filesystem alignment remain separate planned work.