Add missing error codes for silent false categories

[a6b8]

Problem

Categories like supportsMcpApps, hasUiToolLinkage, supportsDisplayModes are reported as false but no diagnostic messages explain why. The user gets no actionable feedback.

Solution

Add error codes:

• UIV-080 — MCP Apps extension not declared
• UIV-081 — Extension version not specified
• UIV-013 — HTML content appears invalid (renamed from duplicate UIV-011)
• UIV-041 — No display modes declared
• UIV-062 — No tools linked to UI resources
• UIV-063 — Tool has UI metadata but no resourceUri

Affected Files

• src/task/CapabilityClassifier.mjs
• src/task/UiResourceValidator.mjs
• src/McpAppsValidator.mjs
• Tests for all above