config: simplify runtime environment model

TASKS.md

@@ -2,15 +2,15 @@
 
 ## Current
 
-### `feat/rust-docker-build-cache`
+### `feat/runtime-env-simplification`
 
 Status: in_progress
 
 DoD:
-- Rust Docker builds use a cache-friendly multi-stage layout
-- `admin-api` and `mcp-server` reuse dependency layers across rebuilds
-- noisy local artifacts are excluded from Docker build context
-- deployment fails early when required secret-store env is missing
+- runtime uses component-based PostgreSQL config as the primary model
+- `CRANK_BASE_URL` replaces split public URL variables
+- deployment uses one GitHub secret per runtime env variable
+- deprecated env variables are removed from compose, examples, and docs
 
 ## Next