Add read-only Hermes Tweet signal skill

[kriptoburak]

Summary

Adds a focused, read-only Hermes Tweet signal-brief skill for Hermes Agent.

• uses tweet_explore for offline route discovery
• uses tweet_read for catalog-listed public reads
• explicitly excludes tweet_action
• produces source-linked observations with pagination and coverage caveats
• adds the skill to every README and client setup touchpoint

Validation

• generic Skill validator passes
• all 27 active skill directories exactly match the README table
• all 27 active directories exactly match the client directory list
• all 6 whole-collection install loops exactly match those directories
• README and client structure trees include the skill once
• git diff --check passes

The branch was rebuilt from current main. Obsolete academic-slides cleanup from the old branch was dropped because upstream already completed that retirement.

[kriptoburak]

Rebuilt from current main as a distinct read-only signal-brief workflow. The obsolete academic-slides repair is gone; the skill now uses only tweet_explore and tweet_read, and all 27 active directories match the README, client list, and all 6 install loops. Validation passes and the conflict is resolved.