docs: drop references to the MCP initialization handshake (SEP-2575)

[tadasant]

Summary

MCP is moving to stateless-by-default via SEP-2575 ("Make MCP Stateless", modelcontextprotocol/modelcontextprotocol#2575), which removes the mandatory initialization handshake and replaces it with stateless alternatives (per-request protocol version, server/discover, per-request client capabilities, messages/listen).

Since the initialization handshake is going away, the Server Card docs/schema should stop describing themselves in terms of it. This PR is purely wording / schema-comment cleanup — it reword the handshake-dependent phrasing and changes no schema fields or semantics.

Changes

• README.md — a Server Card "describes a remote MCP server enough for clients to discover and connect to it" (dropped "before initialization").
• docs/discovery.md — discovery "answers where to connect, before any protocol exchange establishes how to communicate" (dropped "complements the lifecycle handshake").
• schema.ts — supportedProtocolVersions doc-comment now reads "Allows clients to select a compatible protocol version before connecting" (dropped "before initialization").
• schema.json — regenerated from schema.ts via npm run generate; the only diff is the doc-comment text above (never hand-edited).

A fresh grep for initiali, handshake, and lifecycle across the tracked repo confirms no remaining handshake-dependent references.

Verification

• npm run check — schema.json is in sync with schema.ts and TypeScript compiles cleanly.
• npm run validate — all 7 examples pass (valid examples validate, invalid examples are rejected).
• npm run format:check on the changed files (README.md, docs/discovery.md, schema.ts, schema.json) — all use Prettier code style.
• Confirmed the schema.json diff matches the schema.ts doc-comment change exactly (no other generated drift).
• CI green on this PR (see checks below).
• Independent fresh-eyes review performed in-session and feedback addressed.

Proof — npm run validate

✓ ServerCard/valid/minimal.json — validated cleanly
✓ ServerCard/valid/templated-remote.json — validated cleanly
✓ ServerCard/invalid/bad-name-pattern.json — rejected (1 error(s))
✓ ServerCard/invalid/date-versioned-schema.json — rejected (1 error(s))
✓ ServerCard/invalid/missing-name.json — rejected (1 error(s))
✓ ServerCard/invalid/missing-schema.json — rejected (1 error(s))
✓ ServerCard/invalid/wrong-schema-name.json — rejected (1 error(s))

All 7 example(s) passed.

Proof — generated schema.json diff

         "supportedProtocolVersions": {
-          "description": "MCP protocol versions actively supported by this remote endpoint. Allows\nclients to negotiate a compatible protocol version before initialization.",
+          "description": "MCP protocol versions actively supported by this remote endpoint. Allows\nclients to select a compatible protocol version before connecting.",

Notes for reviewers

• This is intentionally tightly scoped to handshake-dependent phrasing — no unrelated refactors.
• SEP-2575 is still an open draft; this change is conservative wording cleanup and does not pre-empt the schema decisions under SEP-2127.

🤖 Generated with Claude Code