Add Arcmira API documentation preset for DSH

[zealous1]

What kind of change is this?

• New catalog entry

Adds Arcmira API docs under Boost coding workflow. It is a selectable DSH preset for public API documentation search, not a YouTube research connector. No API key is needed. The preset also exposes submit_feedback, so both the entry and source guide disclose that it is not read-only.

Checklist

• The linked repository resolves, is active, and has an Apache-2.0 license. Its observed GitHub star count is 0.
• The native --patch setup is documented in the project's own DSH guide; the command is copied verbatim. The entry states the cloned-repository working directory and tested DSH version.
• No existing Arcmira README entry or matching PR was found.
• One entry with the current CONTRIBUTING format, no tags or tracking links. The older PR template's tag instruction conflicts with CONTRIBUTING, which explicitly says no tags.
• Coding workflow is the primary use case. Arcmira precedes the existing entries by name.
• Only README.md changes. Generated catalog, badges, ratings, and ranking data are untouched.

Validation and limits

The published native verification script passed on DSH 0.1.7-rc.2 on October 5: real session creation, preset mounting, three-tool discovery, successful documentation search, control-session isolation, and a separately restricted two-tool session. No model inference, credentials, or feedback call were used. The stock YAML exposes all three tools. Loopback Web startup passed, but browser navigation was blocked locally, so browser selection and model-backed Web chat remain unverified.

For this README-only change, git diff --check passed, the upstream PR-format regex accepted the added line, and an isolated run of the upstream build-catalog parsing section retained the full dsh web --patch ... command and correct category. The repository has no scripts/ci.sh; these checks were run directly. No dependencies were installed.

One verifier limitation needs manual review: verify-installs.mjs extracts the final command token, 3086, and searches only the source repository's root README. The exact command is in the linked nested DSH guide instead. I have not claimed the full weekly verifier passes or edited generated verification badges. Please verify against that guide and its reproducible native script. The generated catalog parser does retain the actual start command; clone/cwd prerequisites are in the README entry.