v0.5.0 — App<C> typed config + rtb-vcs git-ops

Milestone tag marking the develop→main cut for framework-spec
milestone 0.5. cargo-release (workspace version bump + crates.io
publish) is deferred — Cargo.toml versions remain at 0.3.0 until
that flow runs separately.

Highlights:

- v0.4.1 — App<C> typed-config integration. App::typed_config<C>
  / config_as<C> / config_schema / config_value via type-erased
  storage + Any::downcast. Application::builder().config<C>(...)
  with Serialize + DeserializeOwned + JsonSchema bound. rtb-cli's
  config show / get / set / schema / validate light up the
  schema-aware paths automatically when the host tool opts in.
  TestAppBuilder::config<C> + config_value<C> for test wiring.

- v0.5 — rtb-vcs git-operations slice. Repo type with init / open
  / clone / walk (async stream) / diff / blame / status / commit
  / fetch / checkout / push. Read paths via gix + gix-blame;
  write paths via shell-out to git per A8 wrap-not-leak.
  Originally-planned git2-fallback Cargo feature obsoleted (A4)
  — consistent backend choice. Auth via rtb-credentials::Resolver
  + inline credential.helper snippet + RTB_VCS_GIT_TOKEN env;
  token never appears in argv. RepoError carries wrapped semantic
  variants; gix / git stderr never leaks. 41 unit tests + Gherkin
  BDD coverage.

- Dependabot wave — schemars 0.8 → 1.x, tantivy 0.22 → 0.26,
  gix-testtools 0.16 → 0.18, tower-http 0.6.8 → 0.6.10, plus
  the routine patch updates.

Per-slice PRs: #39 #40 #41 #42 #49 #50 #51 #52 #53 #54 #55 #56.

Specs:
- docs/development/specs/2026-05-09-v0.4.1-scope.md
- docs/development/specs/2026-05-11-v0.5-scope.md

Component pages:
- docs/components/rtb-vcs.md (new)
- docs/components/rtb-app.md (App<C> updates)
- docs/components/rtb-cli.md (schema-aware config subtree)