What

Three related identifier-handling and dependency fixes, plus CI hardening:

1. Issuer identity is preserved byte-for-byte (RFC 9068 iss, RFC 8414 §3.3). The configured issuer is no longer trailing-slash-stripped before storage, and the AS-metadata issuer comparison no longer strips either side. An issuer carrying a query or fragment component (RFC 8414 §2 forbids both) is rejected at AuthplaneClient.create() with a clear ValueError instead of being silently stripped. .well-known URL derivation still drops the terminating slash — that is derivation (RFC 8414/9728 §3.1), not identity. build_prm_url now preserves the resource's query component and rejects fragment-bearing resources (RFC 8707 §2).
2. The served PRM advertises identifiers verbatim (RFC 9728 §3.3). The adapters serve PRM through upstream MCP's pydantic.AnyHttpUrl fields, which normalise an empty-path authority to a trailing-slash form; clients following the advertised value literally were then rejected by the strict §3.3 comparison. The served document is rewritten so authorization_servers and resource match the configured strings exactly.
3. Security — mcp floor raised to >=1.28.1,<2 (from >=1.23.0,<1.28.0), clearing PYSEC-2026-3483 (affects mcp <=1.28.0). authplane-fastmcp declares the same direct floor since it imports mcp directly. The adapter resolves the URL-elicitation id field from the model's own schema instead of hard-coding the camelCase spelling.
4. CI: the conformance catalog is pinned to a fixed revision, single-sourced in .conformance-catalog-ref (40-hex guarded), with a scheduled drift workflow against the catalog tip; ruff is pinned to >=0.16,<0.17.

Breaking (pre-1.0 → next minor)

• authplane-mcp: supported mcp range is now >=1.28.1,<2. Migration: upgrade mcp to at least 1.28.1; mcp 2.0 is not yet supported.
• Issuers/resources that relied on silent trailing-slash reconciliation or carried query/fragment components must correct their configuration — see the CHANGELOG Migration notes.

Verification

• ruff check + format clean (pinned and latest resolve identically today).
• pyright strict: 0 errors.
• Full suites: 647 passed +1 xfail (root), 67 (mcp), 66 (fastmcp), Python 3.11–3.13.
• Conformance vs the pinned catalog: 104 passed, 1 intentional xfail.
• Manual E2E against a live authserver (develop): PRM served verbatim, RFC 9728 challenge, authenticated MCP initialize + tools/call, 401 on garbage tokens.