docs(migration): warn that customTools["update_rights"] must be removed when upgrading to 6.7.0

[bokelley]

Refs #1438

docs/migration-6.6-to-6.7.md mentioned the update_rights promotion to a framework-registered first-class tool but didn't call out that adopters with a pre-existing customTools["update_rights"] registration must remove it. Without the note, a duplicate registration causes createAdcpServer() to throw at construction time — and for server setups that build tenants lazily (e.g., registry patterns), that error surfaces on the first inbound request as an MCP discovery failure rather than a startup error, making the root cause hard to diagnose. The issue was surfaced by root-cause analysis of #1438.

Changes:

• Add **Breaking for customTools registrations:** note to the update_rights feature bullet in "What else changed," quoting the full error message and explaining the lazy-init discovery-failure symptom
• Add a self-grade checklist item with a grep audit recipe so upgrading adopters have an actionable pre-flight check
• Qualify the section header from "don't need any adopter action" to "don't need any adopter action unless noted inline" to avoid the header misdirecting the very adopters the note targets

No changeset needed (docs-only change, per CLAUDE.md).

What tested:

• npm run format:check — clean
• npm run ci:docs-check — blocked by missing tsx in environment (pre-existing; same gap noted in PR fix(mcp): restore SSE fallback for loopback/private-address MCP servers #1442 body); docs content verified by manual read

Pre-PR review:

• code-reviewer: approved — no blockers; nit on section-header contradiction (addressed in this diff)
• docs-expert: approved after two fix passes — prior blockers (truncated error message, throw-timing ambiguity, duplicated grep) all resolved

Triage-managed PR. This bot does not currently iterate on
review comments or PR conversation threads (only on the source
issue). To unblock:

• Push fixup commits directly: gh pr checkout 1443 →
  fix → push.
• Or re-trigger: comment /triage execute on the source
  issue.

See adcp#3121
for context.

Session: https://claude.ai/code/session_01V1MgRaahiwFFgpMc66eD2k

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[bokelley]

Superseded — recipe #16 on main (docs/migration-6.6-to-6.7.md lines 1007-1029) already covers everything this PR was adding to the feature bullet, including the same error message, the lazy-init / discovery-failure framing, and the grep -rn 'customTools.*update_rights' src/ audit recipe. The conflict that this PR was rebasing against is between (a) main's short bullet pointer ("see recipe #16") and (b) this PR's longer inline duplicate of recipe #16's content. Pointer wins; the recipe is the right place for the long-form explanation. Closing as duplicate of work already on main.

[bokelley]

Understood — acknowledged. Recipe #16 on main is the canonical home; the pointer approach is cleaner than inlining the same content here. Nothing further needed from this PR.

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Generated by Claude Code

[bokelley]

Acknowledged — closing the loop here. PR superseded by Recipe #16 on main; no further action needed.

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Generated by Claude Code

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Generated by Claude Code