AxonOS Radar 12.0.6

The most consequential findings from a full architecture/security/CI pass —
one is a correction to a fix from two releases ago that turned out not to
work in production, and one is a validation gap in the product's actual
primary output.

Fixed

• v12.0.4's report.html correction never actually ran. It was correct
  code, gated behind the same "is the engine's data newer" check as
  everything else in the sync loop — but the push path routinely commits
  data/radar.json and the uncorrected report.html in the same scan, so
  by the time this script runs, that gate is already true and main()
  returns before the FILES loop is ever reached. sync_report_html() is
  now a separate function that runs first, unconditionally, every
  invocation — independent of whether the rest of the data is "new." Worst
  case it's briefly wrong for the ~20-minute offset between the engine's
  scan and this script's schedule, not indefinitely.
• brs, relevance_tier, and relevance_ledger — the current, primary
  scoring system, the entire point of this project — had zero validation
  anywhere in the pipeline. Not in the JSON Schema, not in
  validate_payload.py. Only the legacy v3 evidence_tier fields were
  checked. A malformed score (out of range, wrong type, malformed tier
  string, broken ledger entry) could have shipped to the live map
  undetected. Now validated: brs must be a number 0–100; relevance_tier
  must match L[0-4]_UPPER_SNAKE; relevance_ledger entries must carry
  points (number), kind, and reason. Adversarially tested against
  seven corruption cases (out-of-range, negative, wrong type, bool-as-int,
  malformed tier, out-of-range tier number, missing ledger fields) before
  shipping — each one confirmed caught, and the real 120-project payload
  confirmed to still validate clean.
• docs/DATA_MODEL.md described the v2/v3 schema only — the primary v5
  fields above weren't documented at all, only the legacy ones. Rewritten
  against the actual schema and live data, legacy fields kept and clearly
  marked as superseded-but-still-valid.
• docs/INCIDENT_RESPONSE.md's containment step pointed at disabling a
  workflow ("AxonOS Radar") that's been disabled since the 8.0.0 cutover —
  scanning happens in the private engine now; this repo's own containment
  lever is sync.yml.

Added

• tests/test_validate_payload.py — 22 tests. This script had none before,
  despite being described as "the executable half of the public data
  contract" and despite every other script under scripts/ having
  dedicated coverage.