wiki validate never checks groundings: the Wiki CLI is never given the code graph

[theyashasvipandey]

mex wiki validate never validates groundings. Its report always contains
codeGraphAvailable: false, even in a checkout with a fresh .mex/graph.db, so no grounding
is ever resolved against code.

To reproduce

mex graph            # graph is fresh
mex wiki validate --json

Measured on mex and on a setup-populated Hono scaffold: 0 errors in both, codeGraphAvailable: false in both, including files whose groundings mex check reports as drifted or gone.

Cause

The Wiki CLI builds its service options without a code graph. wiki validate therefore can't
resolve a grounding, and wiki migrate's bodyHash backfill never runs either. Both degrade
silently. This is already recorded in the scaffold's own ROUTER under Known Issues, but it isn't
tracked as an issue:

The Wiki CLI's serviceOptions carries no code graph, so wiki validate cannot resolve a
grounding and wiki migrate's body-hash backfill never runs.

Expected behavior

When a fresh graph exists, pass a read-only graph adapter to the Wiki services so validate
checks groundings and migrate backfills bodyHash. When the graph is missing or stale, keep
today's degraded behaviour and say so, as the notice already does.