prologue: wire background_id into new player creation on server

server/index.js

@@ -1,4 +1,4 @@
-// OTIVM server — OTIVM-III
+// OTIVM server — OTIVM-IV
 // Per-player SQLite integration.
 // TESSERA world database (data/otivm.sqlite3) — read-only, unchanged.
 // Player databases (data/saves/{token}.sqlite3) — one per player,
@@ -7,6 +7,12 @@
 // JSON save files (data/saves/{token}.json) — never deleted, migrated
 //   transparently on first SQLite access if present.
 // Frontend interface unchanged — GET/POST /api/save/:token same as before.
+//
+// Change 3 (OTIVM-IV): background_id from the frontend is now a real
+// canonical identifier (e.g. 'former_legionary'). On new player creation,
+// seed actor_parameters from background_starting_values for that background.
+// The previous default of 'unknown' is kept only as a fallback for legacy
+// saves that predate Change 3.
 
 import Fastify from 'fastify'
 import fastifyStatic from '@fastify/static'
@@ -296,6 +302,13 @@ function autToInt(band) {
 // Writes parameter changes as new actor_parameters rows (append-only).
 // Appends new events to the events table.
 // Marks superseded parameter rows.
+//
+// On new player creation (no actor_profile row yet):
+//   - Uses background_id from the request body (sent by frontend after
+//     player chooses on the Prologue tab).
+//   - Seeds actor_parameters from background_starting_values for that background.
+//   - Sets liquiditas to the background's starting_den value from the body.
+//   - Falls back to 'unknown' only if no background_id is present (legacy saves).
 
 function writePlayerState(token, pdb, body) {
   const now = new Date().toISOString()
@@ -307,29 +320,57 @@ function writePlayerState(token, pdb, body) {
   ).get(actorId)
 
   if (!profile) {
+    // New player — use the background_id sent by the frontend.
+    // The Prologue tab ensures this is a canonical identifier before sending.
+    const backgroundId = body.background_id || 'unknown'
+    const actorName    = body.actor_name    || 'Mercator'
+
     pdb.prepare(`
       INSERT OR IGNORE INTO actor_profile
         (actor_id, session_id, background_id, actor_name, epoch, schema_version, recorded_at)
-      VALUES (?, ?, ?, ?, 'roman_14bce', 3, ?)
+      VALUES (?, ?, ?, ?, 'roman_14bce', 4, ?)
-    `).run(
+    `).run(actorId, actorId, backgroundId, actorName, now)
-      actorId,
+
-      actorId,
+    // Seed all parameters from background_starting_values for chosen background.
-      body.background_id || 'unknown',
+    // auctoritas gets value_social seeded from the same row's value_true.
-      body.actor_name    || 'Mercator',
-      now
-    )
-    // Seed parameters from background_starting_values
     pdb.prepare(`
       INSERT OR IGNORE INTO actor_parameters
         (actor_id, parameter_token, scope, layer,
-         value_true, value_perceived, confidence_tag, observable_level,
+         value_true, value_perceived, value_social,
-         drift_source, recorded_at)
+         confidence_tag, observable_level, drift_source, recorded_at)
-      SELECT ?, parameter_token, 'actor', 'roman',
+      SELECT
-             value_true, value_perceived, confidence_tag, observable_level,
+        ?, parameter_token, 'actor',
-             'initial', ?
+        CASE WHEN parameter_token IN ('auctoritas','clientela','liquiditas','fama',
+             'disciplina','mercatus_scientia','itineris_scientia','ius_accessus',
+             'periculum_tolerantia','negotiatio','litterae','officia_burden')
+             THEN 'roman' ELSE 'universal' END,
+        value_true, value_perceived,
+        CASE WHEN parameter_token = 'auctoritas' THEN value_true ELSE NULL END,
+        confidence_tag, observable_level, 'initial', ?
       FROM background_starting_values
       WHERE background_id = ?
-    `).run(actorId, now, body.background_id || 'unknown')
+    `).run(actorId, now, backgroundId)
+
+    // Override liquiditas with the den value from the body (which was set
+    // from BACKGROUNDS[x].starting_den on the frontend). This is the
+    // authoritative starting value — the seed row is superseded immediately.
+    if (body.den !== undefined) {
+      // Supersede the seed row
+      pdb.prepare(`
+        UPDATE actor_parameters
+        SET superseded_at = ?
+        WHERE actor_id = ? AND parameter_token = 'liquiditas' AND superseded_at IS NULL
+      `).run(now, actorId)
+      // Insert the confirmed starting value
+      pdb.prepare(`
+        INSERT INTO actor_parameters
+          (actor_id, parameter_token, scope, layer,
+           value_true, value_perceived,
+           confidence_tag, observable_level, drift_source, recorded_at)
+        VALUES (?, 'liquiditas', 'actor', 'roman',
+                ?, ?, 'measured', 'full', 'initial', ?)
+      `).run(actorId, String(body.den), String(body.den), now)
+    }
   }
 
   // Update liquiditas if den changed
@@ -540,7 +581,7 @@ fastify.setNotFoundHandler((req, reply) => {
 
 try {
   await fastify.listen({ port: 3000, host: '0.0.0.0' })
-  console.log('OTIVM server running on port 3000 — OTIVM-III')
+  console.log('OTIVM server running on port 3000 — OTIVM-IV')
 } catch (err) {
   console.error(err)
   process.exit(1)