fix(container-runtime): drop prettier from the build script

[dr-bonez]

Problem

Every StartOS build was rewriting container-runtime/src/**/__fixtures__/*.ts from double quotes to single quotes.

Root cause: the container-runtime build script ran prettier . --write from inside the project directory. Since #3437 removed the local prettier config, that invocation resolves the root .prettierrc.json (config files walk up the tree) but not the root .prettierignore (ignore files only resolve from the cwd) — so the **/__fixtures__/ protection never applied. Verified with prettier --file-info: the same fixture file reports ignored: false from the project cwd and ignored: true from the repo root.

make start-os-format/-check had the same bug via the local format/format:check npm scripts.

Fix

• build script is now just rm -rf dist && tsc; the local format/format:check scripts and the prettier devDependency are removed — one root prettier config, no per-component prettier surface.
• start-os-format/start-os-format-check are Rust-only, matching start-wrt/start-tunnel; TS formatting for web + container-runtime runs through web-format (root cwd, so the ignore applies).
• Updated the docs that still described the pre-chore(fmt): normalize formatting — one config per language, reproducible rustfmt #3437 setup (local config, double quotes, build-time formatting) in projects/start-os/{AGENTS,CONTRIBUTING}.md and container-runtime/{AGENTS,CONTRIBUTING}.md.
• Lockfile regenerated with pinned npm 11.13.0: drops prettier and syncs the file: SDK dist entry to 2.0.3 (matches the SDK version at HEAD).

No changelog entry — build tooling only, nothing user-visible.

Verification

• npm run build exits 0 and leaves the tree untouched (fixtures stay double-quoted)
• npx prettier --check from the root passes over container-runtime and the edited docs
• container-runtime jest suite: 12 tests, 6 snapshots, all pass
• make -n start-os-format start-os-format-check parses and shows the expected Rust-only recipes