--- type: Changed pr: 795 --- Make per-runtime config-mutation dispatch in the installer explicit: a new runtime config adapter registry maps each supported runtime to a typed config intent (install surface, shared-settings gate, finish-phase permission writer), and `install()`/`finishInstall()` dispatch by resolved intent instead of inline `runtime === '...'` branching. Behavior-preserving; unknown runtimes now fail loudly. (#60)