feat: select the TechLog Studio adapter from runtime configuration

Adds TECH_LOG_STUDIO_SOURCE (MOCK | HTTP, default MOCK) to the V2 runtime
config schema so a build can switch createTechLogFeatureInstalledInput
between the mock and HTTP Studio gateways without a rebuild. V1 documents
predate the key and always normalize to MOCK. The HTTP gateway is
constructed with only { operations } per Task 4's actual signature -
no CSRF provider is wired here; that lands with attachCredentials at a
later composition-root task.

Updates every existing Studio test call site to the new required
createTechLogFeatureInstalledInput(context) signature via a shared
tests/helpers/studio-install-context.ts MOCK fixture, so the whole
existing Studio suite keeps exercising the mock adapter unchanged.

tests/unit/release-coherence.test.ts

@@ -75,6 +75,7 @@ const runtimeV2 = {
     OFFLINE_COMMANDS: "DEFAULT",
   },
   FEATURE_OVERRIDES: {},
+  TECH_LOG_STUDIO_SOURCE: "MOCK",
 } as const satisfies RuntimeConfigArtifact;
 
 async function releaseV2With(

tests/unit/runtime-adapters.test.ts

@@ -27,6 +27,7 @@ const runtime: Runtime = {
       OFFLINE_COMMANDS: "DEFAULT",
     },
     FEATURE_OVERRIDES: {},
+    TECH_LOG_STUDIO_SOURCE: "MOCK",
   },
   configSchema: "V2",
   build: {