vgsp: channel-reuse reconciliation + first-attempt readiness (fresh on 54a41db2)

Net port of the stallfree work onto master without the reverted hint-stop:

- Channel-reuse reconciliation, provably safe: svc_chan_registration marks
  a genuinely new binding (!same_gen) with wd_chanswitch; the first pump
  pass drops opdef slots bound to the reused handle ONLY when their
  first-pending stamp predates the reconcile instant (time_before), so a
  slot the fresh binding creates (after registration, at/after the
  reconcile) can never be touched; logs reason=stale-entry-chanswitch when
  the ring already carries content. Captures stay enabled (the fresh
  client's own entries may already be at slot 0).
- First-attempt readiness (r229/r231: attempt 1 stalls, attempt 2 works
  once the 10 s rebuild cadence caught up): a genuinely new binding gets a
  3 s freshness window (wd_newbind_until, SVC_GR_NEWBIND_MS) in which the
  pump (a) does NOT silently consume a GR entry that decoded nothing (no
  release/QMD/ops, non-replay) - it holds it and requests an immediate
  rebuild (svc.rebuild_now, consumed at the top of the service loop before
  the next pump), and (b) does the same for a GR entry whose page is
  unmapped. The entry re-evaluates with resolved pages inside the window,
  so the launch executes on the FIRST attempt; after the window entries
  consume as before (<=3 s extra on first contact).
- Token: 'vgsp-gr: GR-STALL-pending-map h=... va=... entry=... action=rebuild
  reason=stale-entry-newbind' (bounded 16/session).
- No hint-stop (master's revert already removed it; kept absent - the
  re-post window is the delivery bridge for late-registered events).
- f0789007 kill-recovery, the r220 hold guard and the m181 arm rule are
  untouched (already present on this base).

make kernel green (0 errors, pre-existing warnings only).

0 files changed, 0 insertions, 0 deletions