docs: validate all MCP servers with protocol handshake

- Added matomo-mcp, mcp-redmine, paperless-mcp to working servers list
- Documented runtime failures (nextcloud, imap, webserial, kicad)
- Documented transport mismatches (postizz, penpot)
- Updated README.md vendor count and date
- Added JOURNAL entry for mock credential validation

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Assisted-by: GLM-5 via Crush <crush@charm.land>

JOURNAL.md

@@ -1779,3 +1779,37 @@ echo '{"jsonrpc":"2.0","method":"initialize","id":1,"params":{"protocolVersion":
 - STATUS.md
 
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+
+### MCP Protocol Validation with Mock Credentials
+
+**Date/Time**: 2026-02-19 17:30:00 EST
+**Work**: Validated MCP handshake for all config-required servers
+
+**What was done**:
+
+Validated the 8 servers that "require config" to determine if MCP protocol layer works without real backend connections:
+
+**Validated Successfully (MCP handshake works):**
+- matomo-mcp: ✅ Connects to openmost.io hosted service, responds to MCP handshake (59 tools, 31 prompts)
+- mcp-redmine: ✅ MCP handshake works without live server connection
+- paperless-mcp: ✅ MCP handshake works with CLI args (baseUrl + token)
+
+**Runtime Failures (crash before MCP protocol):**
+- nextcloud-mcp: ❌ Crashes on startup - requires reachable OAuth endpoint
+- imap-mcp: ❌ Crashes on startup - requires reachable IMAP server
+- webserial-mcp: ❌ Crashes on startup - requires WebSocket bridge server
+- kicad-mcp: ❌ Crashes on startup - requires pcbnew Python module
+
+**Transport Mismatch:**
+- postizz-mcp: ❌ Uses HTTP transport (port 3084), not stdio - incompatible with standard MCP clients
+
+**Updated STATUS.md** with accurate validation status for all servers.
+
+**Final Validation Summary**:
+- Working MCP servers (validated handshake): 17
+- Runtime failures (need live backend): 4
+- Transport mismatch (not stdio): 2 (postizz, penpot)
+- Build failures: 4 (discourse, reverse-engineering-assistant, snipeit, proxmox, mcp-ansible)
+- Blocked: 1 (wordpress)
+
+---