Follow the repository rename to opal-cpp

[aaylward]

Follow-through for the repository rename muchq/smithy-cpp → muchq/opal-cpp (after #201's three surfaces landed).

What

Everything that named the repository now says opal-cpp:

• README: title, and the intro now names the runtime (opal) alongside the generators. CONTRIBUTING.md, both issue templates, the docs (PLAN.md, runtime.md, versioning.md, development.md, the guides, three ADRs' prose), the quickstart's git_override remote and issue links, and the CHANGELOG header and release links.
• Two strings that carried the old name outward, so the rename is not only cosmetic:
  • The client's default User-Agent is opal-cpp/<version>. tools/release.sh asserts and rewrites it, and tools/release_test.sh covers that, so both moved with it. Called out as Breaking in the CHANGELOG: anything matching on the old product token needs the new one.
  • The banner on generated files: Code generated by opal-cpp (cpp-codegen). Printed by the emitters (with the Java test that asserts it), goldens regenerated from them, byte-identical on a second run.
• ADR-0024 addendum recording the rename, which the ADR and Stop naming runtime surfaces after the IDL: audit smithy in generated code and runtime deps #201 had put out of scope, and noting the User-Agent was the one wire-visible string the original audit missed.

Kept: codegen/smithy-cpp-codegen is the Smithy plugin's directory and Gradle project, the one thing here named for the IDL on purpose. docs/superpowers/ is untouched (it records local paths from a past session). The old URL redirects, so nothing that still says smithy-cpp breaks.

Testing

• bazel test //... --config=werror: 129 tests pass.
• examples/bazel-consumer: 15 tests pass.
• cd codegen && gradle build spotlessCheck passes; goldens regenerate byte-identically.
• tools/release_test.sh passes against the new User-Agent token.
• buildifier and clang-format clean.

Checklist

• Tests added/updated for the change (the release-script test and the Java banner test assert the new strings)
• bazel test //... and (cd codegen && gradle build spotlessCheck) pass locally
• Formatting clean (clang-format, buildifier, spotless)
• Architectural decisions recorded as an ADR (ADR-0024 addendum)

🤖 Generated with Claude Code

https://claude.ai/code/session_01Jj5X2fKdgrYurHmbwLzUiQ

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