Pipeline: Add LLM and mocked user generation to the pipeline (#230)

docs/pipeline/diagrams/current/activity.puml

@@ -93,6 +93,77 @@ while (For each sampled Location?) is (Remaining cities)
   endif
 endwhile (Done)
 
+|#EAF0E8|BiergartenPipelineOrchestrator|
+:GenerateUsers(enriched_cities);
+
+|#E2EBDC|JsonLoader|
+:LoadPersonas("personas.json");
+:LoadForenamesByCountry("forenames-by-country.json");
+:LoadSurnamesByCountry("surnames-by-country.json");
+note right
+  Each call is cached after its first parse.
+  MockCuratedDataService (--mocked) returns a
+  fixed in-memory dataset instead and skips
+  these three JSON files entirely.
+end note
+
+|#EAF0E8|BiergartenPipelineOrchestrator|
+while (For each EnrichedCity?) is (Remaining cities)
+  :SampleName(forenames_by_country,\n  surnames_by_country, location.iso3166_1);
+  if (Names available for country?) then (no)
+    :Log warning, skip city;
+  else (yes)
+    :Sample UserPersona (uniform random);
+
+    |#E5EDE1|DataGenerator|
+    if (Generator Mode) then (MockGenerator)
+      :DeterministicHash & Format;
+    else (LlamaGenerator)
+      :prompt_directory_->Load("USER_GENERATION");
+      note right
+        Resolves to USER_GENERATION.md inside --prompt-dir.
+      end note
+      repeat
+        :Infer(system_prompt, user_prompt, max_tokens, kUserJsonGrammar);
+        :ValidateUserJson(raw, user);
+        if (Is JSON Valid?) then (yes)
+          break
+        else (no)
+          :Attempt++;
+          :Append validation error to retry prompt;
+        endif
+      repeat while (Attempt < 3?) is (yes)
+    endif
+
+    |#EAF0E8|BiergartenPipelineOrchestrator|
+    if (Generation successful?) then (yes)
+      :BuildEmail(name, used_email_local_parts);
+      :GenerateDateOfBirth(rng);
+      note right
+        email and date_of_birth are generated
+        programmatically, never LLM-authored.
+      end note
+
+      |#E0EAE0|SqliteExportService|
+      :ProcessRecord(UserRecord);
+      if (Location in cache?) then (yes)
+        :Reuse location_id;
+      else (no)
+        :Insert Location & Cache ID;
+      endif
+      :Insert User (FK: location_id);
+
+      if (Exception caught during insert?) then (yes)
+        |#EAF0E8|BiergartenPipelineOrchestrator|
+        :Log warning "SQLite export failed";
+      else (no)
+      endif
+    else (no)
+      :Log warning "Generation failed, skipping...";
+    endif
+  endif
+endwhile (Done)
+
 |#EAF0E8|BiergartenPipelineOrchestrator|
 :GenerateBreweries(enriched_cities);