v0.6.0 — kill the verbose flag, jsonSchema is the only dial

Breaking change to /run. v0.5.0's two-flag matrix (verbose + jsonSchema)
collapses to one — jsonSchema decides everything:

  no jsonSchema → {runId, workspace, exitCode, text}                 (lean)
  jsonSchema    → {runId, workspace, exitCode, text, json,           (full)
                   events, sessionId, usage}
                  + {parseError, jsonRetries} (replaces json) on
                    schema-validation failure after 3 retries
                    (everything else still surfaces for debugging)

Schema mode is always-verbose. Want events without strict validation?
Pass "jsonSchema": {"type": "object"} — permissive, just forces JSON
output.

The verbose field is removed from the request model. Pydantic silently
ignores stale verbose=true callers (extra=ignore) — they get the lean
text response without a 422.

Migration:
  - drop verbose=true; if you wanted events/sessionId/usage, set
    jsonSchema (use {"type":"object"} for permissive)
  - schema-set callers now also receive text + events + sessionId +
    usage alongside json
  - SDK regen recommended