Docs: disclose MCP anonymous usage ping

[r3dbars]

Summary

• rebuild the intended Docs: disclose the MCP helper's anonymous usage ping #1357 telemetry disclosure on fresh main
• add plain-language disclosure to docs/agent-connect.md
• add technical telemetry gating/details to Tools/TranscriptedMCP/README.md
• intentionally did not bring over unrelated Docs: sync agent-surface docs with actual behavior #1356 stacked docs sync changes

Checks

• git diff --check
• bash scripts/dev/agent-preflight.sh origin/main
• swift test --package-path Tools/TranscriptedMCP — 131 passed
• bash run-e2e-smoke.sh

#1357 status

• Docs: disclose the MCP helper's anonymous usage ping #1357 was closed while stacked on Docs: sync agent-surface docs with actual behavior #1356; this is the fresh main-based replacement docs slice.

COORD_DONE: GREEN | PRs opened: this tiny draft docs PR | stale PRs salvaged/held: #1357 salvaged here, #1356 not included | checks run: diff-check, agent-preflight, MCP swift test, e2e smoke | lanes used: Codex=rebuilt/tested/opened PR; Claude=skipped unavailable; Local=skipped not needed; Windows=skipped unavailable | smallest next action: review and merge after CI

[r3dbars]

Closing as superseded by the rebuilt clean docs-only PR #1378 after #1375 made this draft branch dirty.