Add user generation feature

docs/pipeline/diagrams/planned/activity.puml

@@ -43,7 +43,7 @@ fork again
   :EnrichmentService::PreWarmLocationCache(sampled_locations);
 end fork
 fork
-  :JsonLoader::LoadNamesByCountry("names-by-country.json");
+  :JsonLoader::LoadNamesByCountry(\n  "forenames-by-country.json",\n  "surnames-by-country.json");
 fork again
   :JsonLoader::LoadPersonas("personas.json");
 end fork

docs/pipeline/diagrams/planned/class.puml

@@ -67,11 +67,47 @@ package "Domain: Models" {
   }
 
   class UserResult {
+    + first_name : std::string
+    + last_name : std::string
+    + gender : std::string
     + username : std::string
     + bio : std::string
     + activity_weight : float
   }
 
+  class Name {
+    + first_name : std::string
+    + last_name : std::string
+    + gender : std::string
+  }
+
+  class ForenameEntry {
+    + name : std::string
+    + gender : std::string
+  }
+
+  class NamesByCountry {
+    - forenames_by_country_ : std::unordered_map<std::string, std::vector<ForenameEntry>>
+    - surnames_by_country_ : std::unordered_map<std::string, std::vector<std::string>>
+    + SampleName(iso3166_1 : const std::string&,\n  rng : std::mt19937&) : std::optional<Name>
+  }
+
+  note right of NamesByCountry
+    Backed by two source-shaped maps,
+    keyed by ISO 3166-1 country code,
+    sourced from popular-names-by-country-dataset
+    (CC0) -- see ETHICS-AND-KNOWN-ISSUES.md.
+    Gender is preserved per forename so it can
+    be threaded through to persona/bio generation
+    later; surnames carry no gender in the source
+    data. Pairing happens at sample time, not at
+    fixture-authoring time, so no information from
+    the source dataset is discarded up front.
+  end note
+
+  NamesByCountry *-- "0..*" ForenameEntry
+  NamesByCountry ..> Name : produces
+
   class CheckinResult {
     + checked_in_at : std::string
     + note : std::string
@@ -110,9 +146,20 @@ package "Domain: Models" {
     + user_id : uint64_t
     + location : Location
     + user : UserResult
+    + email : std::string
+    + date_of_birth : std::string
+    + password : std::string
     + metadata : GenerationMetadata
   }
 
+  note right of GeneratedUser
+    email, date_of_birth, and password are
+    programmatically generated by the orchestrator
+    (not LLM-authored) so a downstream auth-account
+    seeding consumer can register real accounts from
+    this export. See ROADMAP.md §1.
+  end note
+
   class GeneratedCheckin {
     + checkin_id : uint64_t
     + user_id : uint64_t
@@ -321,15 +368,15 @@ package "Infrastructure: Data Preloading" {
   interface DataPreloader <<interface>> {
     + LoadLocations(filepath : const std::filesystem::path&) : std::vector<Location>
     + LoadBeerStyles(filepath : const std::filesystem::path&) : std::vector<BeerStyle>
-    + LoadPersonas(filepath : const std::filesystem::path&) : std::vector<Persona>
-    + LoadNamesByCountry(filepath : const std::filesystem::path&) : NamesByCountry
+    + LoadPersonas(filepath : const std::filesystem::path&) : std::vector<UserPersona>
+    + LoadNamesByCountry(forenames_filepath : const std::filesystem::path&,\n  surnames_filepath : const std::filesystem::path&) : NamesByCountry
   }
 
   class JsonLoader {
     + LoadLocations(filepath : const std::filesystem::path&) : std::vector<Location>
     + LoadBeerStyles(filepath : const std::filesystem::path&) : std::vector<BeerStyle>
-    + LoadPersonas(filepath : const std::filesystem::path&) : std::vector<Persona>
-    + LoadNamesByCountry(filepath : const std::filesystem::path&) : NamesByCountry
+    + LoadPersonas(filepath : const std::filesystem::path&) : std::vector<UserPersona>
+    + LoadNamesByCountry(forenames_filepath : const std::filesystem::path&,\n  surnames_filepath : const std::filesystem::path&) : NamesByCountry
   }
 
 }
@@ -380,7 +427,7 @@ package "Infrastructure: Data Generation" {
   interface DataGenerator <<interface>> {
     + GenerateBrewery(location : const Location&,\n  context : const LocationContext&) : BreweryResult
     + GenerateBeer(brewery_id : uint64_t,\n  location : const Location&,\n  context : const LocationContext&,\n  style : const BeerStyle&) : BeerResult
-    + GenerateUser(location : const Location&) : UserResult
+    + GenerateUser(city : const EnrichedCity&,\n  persona : const UserPersona&,\n  name : const Name&) : UserResult
     + GenerateCheckin(user : const GeneratedUser&,\n  brewery : const GeneratedBrewery&,\n  timestamp : const std::string&) : CheckinResult
     + GenerateRating(user : const GeneratedUser&,\n  beer : const GeneratedBeer&,\n  checkin_id : uint64_t) : RatingResult
   }