Align mcp-server-dev skills with claude.com/docs connector guidance (#1418)

- build-mcp-server: load llms-full.txt for Claude-specific context;
  add Phase 6 (test in Claude, review checklist, submit, ship plugin)
- references/auth.md: add Claude auth-type table, callback URL,
  not-supported list
- references/tool-design.md: add Anthropic Directory hard requirements
  (annotations, name length, read/write split, prompt-injection rule)
- build-mcp-app: add Claude host specifics (prefersBorder,
  safeAreaInsets, CSP) and submission asset specs; testing via
  custom connector
- build-mcpb: note remote servers are the recommended directory path

plugins/mcp-server-dev/skills/build-mcp-server/SKILL.md

@@ -8,6 +8,8 @@ version: 0.1.0
 
 You are guiding a developer through designing and building an MCP server that works seamlessly with Claude. MCP servers come in many forms — picking the wrong shape early causes painful rewrites later. Your first job is **discovery, not code**.
 
+**Load Claude-specific context first.** The MCP spec is generic; Claude has additional auth types, review criteria, and limits. Before answering questions or scaffolding, fetch `https://claude.com/docs/llms-full.txt` (the full export of the Claude connector docs) so your guidance reflects Claude's actual constraints.
+
 Do not start scaffolding until you have answers to the questions in Phase 1. If the user's opening message already answers them, acknowledge that and skip straight to the recommendation.
 
 ---
@@ -182,6 +184,17 @@ Tools are one of three server primitives. Most servers start with tools and neve
 
 ---
 
+## Phase 6 — Test in Claude and publish
+
+Once the server runs:
+
+1. **Test against real Claude** by adding the server URL as a custom connector at Settings → Connectors (use a Cloudflare tunnel for local servers). Claude identifies itself with `clientInfo.name: "claude-ai"` on initialize. → https://claude.com/docs/connectors/building/testing
+2. **Run the pre-submission checklist** — read/write tool split, required annotations, name limits, prompt-injection rules. → https://claude.com/docs/connectors/building/review-criteria
+3. **Submit to the Anthropic Directory.** → https://claude.com/docs/connectors/building/submission
+4. **Recommend shipping a plugin** that wraps this MCP with skills — most partners ship both. → https://claude.com/docs/connectors/building/what-to-build
+
+---
+
 ## Quick reference: decision matrix
 
 | Scenario | Deployment | Tool pattern |