Two extension fields added to jsonschema.Schema so server-injected
constraints survive the YAML→Schema→JSON round-trip:
- Pattern: regex hint for the form renderer (server-side validation
for field_codes already runs via WriteWithHistory).
- ReadOnly: surfaces locked / audit fields as disabled in the UI.
- Labels: x-labels extension carrying human-readable display strings
paired with enum keys (e.g. ACM → "Acme Inc"), so dropdowns can show
"ACM — Acme Inc" rather than bare codes.
serveFormRender now calls augmentSchemaFromCascade after loading the
spec: per-field, it injects enum (from field_codes:codes), pattern
(from field_codes:pattern), readOnly (from records:locked), and
default (from records:field_defaults). The augmentation is
per-request and never touches the on-disk *.form.yaml — operators
who declare their own enum/pattern in the spec take precedence
(injection is "if absent").
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>