fix: handle EAP+phase combinations in aggFilters search logic (#11)

Implements all 5 search cases from issue #10:
1. Specific stages only → phase:X Y
2. All stages incl. NA → studyType:int
3. EAP only → studyType:exp
4. EAP + specific stages → studyType:exp,phase:X Y (combined filter)
5. EAP + all stages → studyType:exp

Previously, EAP searches always ignored any phase preference. The fix
adds phase-aware branching inside the is_eap block, combining
studyType:exp with the numbered phase list when specific phases are
requested.

Co-authored-by: claude[bot] <41898282+claude[bot]@users.noreply.github.com>
Co-authored-by: KevinIsInCoding <KevinIsInCoding@users.noreply.github.com>

clinical_trials_guru.py

@@ -328,12 +328,25 @@ def search_trials_api(
         "pageSize": 200,  # max page size; we paginate until exhausted
         "format": "json",
     }
-    # aggFilters accepts only one value; studyType and phase can't be combined.
+    # aggFilters supports comma-separated keys (e.g. "studyType:exp,phase:3 4").
     # RECRUITING status already excludes EAPs, so studyType:int is only needed
     # when no phase filter is applied. studyType:int returns all phases including N/A.
     # Observational studies use studyType:obs; phases don't apply to them.
+    #
+    # Case matrix:
+    #   EAP only                  → studyType:exp
+    #   EAP + specific phases     → studyType:exp,phase:X Y  (combine both filters)
+    #   EAP + all phases          → studyType:exp  (no phase filter needed)
+    #   Interventional, specific  → phase:X Y
+    #   Interventional, all/NA    → studyType:int  (returns NA trials too)
     if is_eap:
-        params["aggFilters"] = "studyType:exp"
+        numbered = [p for p in (phases or []) if p != "na"]
+        if numbered:
+            # EAP + specific phases: combine studyType:exp with phase filter
+            params["aggFilters"] = "studyType:exp,phase:" + " ".join(numbered)
+        else:
+            # EAP only or EAP + all phases (no phase restriction)
+            params["aggFilters"] = "studyType:exp"
     elif is_observational:
         params["aggFilters"] = "studyType:obs"
     elif phases:
@@ -343,8 +356,10 @@ def search_trials_api(
         if numbered:
             params["aggFilters"] = "phase:" + " ".join(numbered)
         else:
+            # Only "na" was requested — use studyType:int (all phases including N/A appear)
             params["aggFilters"] = "studyType:int"
     else:
+        # No phase preference — return all interventional studies including N/A phase
         params["aggFilters"] = "studyType:int"
 
     _logger.info(