Add a judge panel to inspect (engine + scripted config)

Judges replace the single master: each judge independently evaluates the inspectors' reports, and when there are >=2 a chair merges their verdicts into one final verdict with the panel's agreement/dissent surfaced.

• settings: ReviewProfileConfig.Judges []ReviewConfig + Chair (legacy Master/MasterAgent/MasterModel kept for back-compat).
• profile: profileJudges resolves the panel + chair index; profileMaster- Identity now reports the chair/single judge on top of it.
• synthesis: PanelSynthesisProvider fans out to judges in parallel, the chair merges, failures are dropped (tested with stub providers).
• run path: runMultiAgentPath builds the panel provider.
• scripted: --set-judge (repeatable) + --set-chair replace --set-master.