refactor(agent-view): remove non-functional MCP tab; rely on Connect → MCP Servers

[subinium]

Summary

Agent → MCP tab is functionally inert. GET /api/presets hardcodes activeMcp: null (packages/runtime-node/src/index.ts:3402), and agent-view.ts:680 carries the comment "MCP presets have no activation endpoint yet — render as informational only" — so cards in this tab don't even render an Activate button. Meanwhile, the real MCP management (CRUD + reconnect) lives in Connect → MCP Servers and works fine. Two tabs are titled "MCP" with totally different meanings, one of which does nothing.

Evidence

• packages/runtime-node/src/index.ts:3402 — activeMcp: null literal.
• packages/web/ui/src/views/agent-view.ts:680-681 — canActivate is forced false for preset.type === 'mcp'.
• packages/web/ui/src/views/connect-view.ts — /api/mcp/servers GET/POST/DELETE + /api/mcp/servers/:name/reconnect are wired and working.

Scope

packages/web/ui/src/views/agent-view.ts:

• Remove the MCP tab entirely.
• The IdentityTab union becomes 'personas' | 'toolsets'.
• Where the tab used to be, add an inline link: MCP servers → Connect → MCP Servers.

packages/runtime-node/src/index.ts:

• Drop the activeMcp field from the /api/presets response (no consumers after the tab is gone).

Expected impact

• Eliminates a dead tab that confuses users into thinking MCP is broken.
• Removes the "two tabs, both called MCP, different things" naming clash.
• One canonical place to manage MCP (Connect → MCP Servers), matching where the working CRUD lives.

Acceptance criteria

• Agent view has only Personas and Toolsets tabs
• MCP server management is reachable in one click from Agent view (link/banner)
• No dashboard reference to a non-functional MCP preset surface

Out of scope

• Adding "MCP presets" as a real concept (none exist today; could be a future feature)
• Changing MCP CRUD itself in Connect

Labels: enhancement, priority/warning, ux, source/audit

[subinium]

Verifier-confirmed shipped via v0.7.x / v0.8.0 / v0.8.1 / v0.8.2 sweeps. The earlier release PR descriptions used range syntax (#230–#240, #241–#250) which does not trigger GitHub auto-close, leaving these in OPEN state despite the implementation landing. v0.8.3 verifier pass confirmed code presence and acceptance criteria via grep and file inspection on main (commit 72fa31b). If acceptance criteria are not actually met for this specific issue, please reopen with the missing detail and it will be picked up in the next sweep.