fleet: the busbar-release plugin template (CI, deps policy, settings)

[MattJackson]

Renders the fleet template (GetBusbar/busbar-release template/ at f6c22cb4160c14fc3958dee4f022daa7a6298f96) into busbar-auth-github:
the workspace skeleton and dependency table, deny.toml, toolchain, the CI (a call to busbar's reusable
plugin-ci.yml at this repo's busbar pin: the fleet harness and its gates), the dependabot bundle workflow, CODEOWNERS,
LICENSE and the community files, the README header, and the declares file (contract_abi generated
from busbar at the pin). Cargo.lock is re-resolved from busbar's lock at the pin (lock parity).

• busbar pin: 68df8203a98da0c71ec6049bbe92fc83fde25ae6 (moved: the repo follows the fleet pin)
• dependency policy: busbar 68df8203a98da0c71ec6049bbe92fc83fde25ae6 (.github/fleet/deps.toml)
• registry: busbar 68df8203a98da0c71ec6049bbe92fc83fde25ae6 (plugins.yaml)

Written by busbar-release plugin heal; the harness gates are fmt, clippy -D warnings, test,
cargo deny, the dep-wall, the socket/TLS ban (BUSBAR-1.6.0.md line 3980), the C-dependency
allow-list, Cargo.lock parity with busbar, the both-ways conformance (RED arm kept) and the kind's kit.

Findings:

• LAYOUT busbar-auth-github: crate dirs ["busbar-auth-github", "busbar-auth-github-plugin"] are not the twin names ["auth-github", "auth-github-plugin"]; the rendered workspace keeps them until they are renamed