Chameleon

Multi-lens review and idiom-judge correctness pass (exhaustive audit of both
paths against real repos).

Fixed

• Stale-index facts fed to the correctness reviewer. The turn-end correctness
  lens grounds the reviewer prompt with caller facts and transitive caller chains
  read from the committed calls snapshot, and the prompt tells the reviewer to
  flag a finding for any listed caller a change would break. Those caller sites
  were never re-verified against the working tree, so after a refactor the
  reviewer was handed callers that no longer exist or no longer call the changed
  function (a deleted file cited with an exact line, a chain through a deleted
  module) and steered to raise a phantom finding. This is the recurring "stale
  index" symptom. Both blocks now re-verify each cited caller against the working
  tree (the file is readable and still references the function) and drop the stale
  ones: the one-hop block recomputes its count, and a transitive chain is
  truncated at its first stale edge (dropped if that shortens it below the hop
  threshold). Advisory grounding, so a renamed caller the snapshot cannot follow
  simply drops rather than misreports.
• The turn-end idiom self-review could truncate an idiom mid-block. Past the
  context cap the idioms/principles text was hard-sliced with no marker, so a cut
  landing inside a counterexample fence could read an anti-pattern as the
  recommended form, or cut a directive mid-sentence and lose its polarity. The
  block now ends with a "truncated; see the file" marker (matching the per-edit
  path) so a shortened block never reads as the complete idiom set.
• The once-per-session idiom-review marker was never aged out. A turn with no
  session id collapsed every marker to one shared file, after which the idiom
  review was skipped indefinitely. The marker namespace is now reaped at
  SessionStart like the other once-per-session markers.
• The multi-lens advisory header overstated its coverage. When the correctness
  lens ran detached (async mode, or on a bare-auth fallback), only the duplication
  lens ran synchronously, yet the header still claimed "correctness + duplication."
  It now names only the lenses that actually ran this turn.
• A duplication pair could be permanently suppressed without ever being shown.
  The multi-lens duplication lens marked a finding "surfaced" before synthesis and
  rendering; an error in between left the marker written but no advisory emitted.
  The mark now happens only after the finding is rendered.
• The duplication lens ignored its own per-session spawn cap under multi-lens,
  running up to the (larger) correctness budget instead. It now honors the
  duplication cap.
• The idiom_judge directive no longer claims an "independent judge is enabled"
  (no separate judge spawns from this gate); it now reads as a high-bar self-review
  instruction, matching what the flag actually does.