Add LOINC assessment lookup with FHIR snippets

[aanishs]

Clinician value

Give clinicians and implementers a quick lookup for common mental health assessment codes and copyable FHIR examples.

Scope

• Start with PHQ-9, GAD-7, PCL-5, AUDIT-C, DASS-21, WHO-5, PSS-10, and ASRS where source data allows.
• Show panel code, total score code when available, answer/scoring notes, and source links.
• Generate copyable FHIR Observation and QuestionnaireResponse examples using synthetic placeholders only.

Acceptance checks

• Each assessment page makes the primary LOINC code easy to find.
• FHIR snippets are valid-looking examples with no real patient data.
• Each code row has source provenance and last checked date.
• Copy warns clinicians not to paste real client details into public tools.