Opt-in remaining high-fail MCPs (smolify, deepwiki, mobbin)

[justrach]

Summary

Treat remaining high-fail, low-volume MCP servers the way Smolify should be treated: opt-in, not auto-connected.

Smolify on the dirty tree was flipped to require GRAFF_SMOLIFY=1 / GRAFF_SMOLIFY_ACCESS (reverted with that patch; this issue is the durable request). Copy that pattern to deepwiki and mobbin.

Evidence (traces)

Server / tool	calls	err %
mcp__smolify__*	4	25% (29-run sample said 100%; n is tiny either way)
mcp__deepwiki__ask_question	26	30.8% (p50 15s)
mcp__deepwiki__read_wiki_contents	1	100%
mcp__mobbin__search_screens	5	40% (p50 24s)

None of these are required for local coding. They add catalog bytes and fail slowly.

Proposed shape

• Smolify: do not connectSmolify unless GRAFF_SMOLIFY or GRAFF_SMOLIFY_ACCESS is set. (GRAFF_NO_SMOLIFY as the only off-switch is the wrong default.)
• deepwiki / mobbin: same opt-in env (or a single GRAFF_MCP_OPTIONAL=deepwiki,mobbin allow-list). Offline / unauthenticated calls should not sit in the default catalog.
• Prompt must not mention servers that are not connected.

Non-goals

• codedb-pro (licensed path is the opposite: lean in when healthy).
• Hiding webfetch as part of this issue (optional, separate, low volume).

[justrach]

Shipped in v0.0.277 (d422ee8, PR #630). smolify now requires GRAFF_SMOLIFY / GRAFF_SMOLIFY_ACCESS (session_start.zig gates connectSmolify; GRAFF_NO_SMOLIFY stays a force-off), and deepwiki/mobbin connect only with GRAFF_MCP_OPTIONAL=deepwiki,mobbin or GRAFF_DEEPWIKI / GRAFF_MOBBIN (mcp_boot.zig skipOptionalServer). The prompt only describes servers that actually connected. Follow-on: PR #636 (v0.0.278) drops bundled Smolify entirely.