Add documentation for encounters without appointments query

Author: sonzsara

Care/Encounter/encounters_without_appointments_ssmm.md

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+
+# Encounters Without Appointments 
+
+> One row per patient's earliest op encounter that was created without a linked appointment
+
+## Purpose
+
+Identifies op (`encounter_class = 'amb'`) encounters at SSMM that were created **without** a linked appointment (`appointment_id IS NULL`) .
+
+## Parameters
+
+| Parameter | Type | Description | Example |
+|-----------|------|-------------|---------|
+| `date` | DATE / range | Metabase date filter (required, bound to `e.created_date`) | `'2026-07-01'` |
+
+---
+
+## Query
+
+```sql
+SELECT 
+    p.name AS patient_name,
+    pi.value AS ssmm_id,
+    e.created_date,
+    TRIM(COALESCE(u.first_name, '') || ' ' || u.last_name, '') AS created_by
+FROM emr_encounter e
+JOIN emr_patient p
+    ON e.patient_id = p.id
+LEFT JOIN emr_patientidentifier pi
+    ON p.id = pi.patient_id
+   AND pi.config_id = 21
+LEFT JOIN users_user u
+    ON e.created_by_id = u.id
+WHERE e.encounter_class = 'amb'
+  AND e.appointment_id IS NULL
+  --AND {{date}}
+ORDER BY e.patient_id, e.created_date;
+```
+
+## Notes
+
+- Results are effectively ordered by patient (via `DISTINCT ON`), then earliest encounter date within each patient.
+
+*Last updated: 2026-07-24*