Implement dynamic leader hiring costs and improved assignment UI

- Add scaling leader hire costs based on number of leaders already owned (costScalePerOwned: 0.5), making it progressively more expensive to hire multiple leaders and preventing cheap roster stockpiling
- Add leaderHireCost() function in VegaLogic.js to calculate scaled hire costs
- Add unassignLeader() function to allow removing leader assignments
- Update AI in VegaLeaders.js to use dynamic pricing when deciding to hire leaders
- Add research videos for ursaal, kkrix, and mekhan factions
- Enhance leader screen UI with:
  - Dynamic cost display reflecting current scaling
  - Fleet labeling showing ship composition and location
  - Assign/Reassign buttons with list picker for colonies (admins) and fleets (captains)
  - Unassign button for posted leaders
  - Better location display for assigned leaders

data/mastervega-artwork.json

@@ -213,10 +213,10 @@
   "researchVideos": {
     "human":     { "key": "vega-research-human",     "path": "assets/videos/vega/research-human.mp4" },
     "kestrelli": { "key": "vega-research-kestrelli", "path": "assets/videos/vega/research-kestrelli.mp4" },
-    "ursaal":    { "key": "vega-research-ursaal",    "path": null },
+    "ursaal":    { "key": "vega-research-ursaal",    "path": "assets/videos/vega/research-ursaal.mp4" },
     "umbrix":    { "key": "vega-research-umbrix",    "path": null },
-    "kkrix":     { "key": "vega-research-kkrix",     "path": null },
+    "kkrix":     { "key": "vega-research-kkrix",     "path": "assets/videos/vega/research-kkrix.mp4" },
-    "mekhan":    { "key": "vega-research-mekhan",    "path": null },
+    "mekhan":    { "key": "vega-research-mekhan",    "path": "assets/videos/vega/research-mekhan.mp4" },
     "rrashaa":   { "key": "vega-research-rrashaa",   "path": null },
     "cerebrai":  { "key": "vega-research-cerebrai",  "path": "assets/videos/vega/research-cerebrai.mp4" },
     "ssakar":    { "key": "vega-research-ssakar",    "path": "assets/videos/vega/research-ssakar.mp4" },

data/mastervega-rules.json

@@ -372,6 +372,11 @@
     { "id": "elissedra", "name": "Elis Sedra",      "kind": "captain", "hireCost": 210, "upkeep": 6, "portraitFrame": 15, "skills": { "shipAttack": 25, "shipDefense": 15, "initiative": 2 }, "bio": "Flag officer. Give her a battleship and stay out of the way." }
   ],
 
+  "leaderHiring": {
+    "_readme": "Each leader already on an empire's roster raises what the NEXT one costs that empire — see VegaLogic.js leaderHireCost. costScalePerOwned 0.5 means: 1st leader = list price, 2nd = 1.5x, 3rd = 2x, 4th = 2.5x, 5th = 3x, 6th (the roster cap) = 3.5x. Keeps the shared 16-leader pool from being cleared cheaply by whoever stockpiles BC fastest, without changing the cost of a first hire at all.",
+    "costScalePerOwned": 0.5
+  },
+
   "galaxySizes": [
     { "id": "small",  "name": "Small",  "stars": 24, "width": 2600, "height": 1700, "maxEmpires": 4, "desc": "Cramped. You will meet your neighbours early and often." },
     { "id": "medium", "name": "Medium", "stars": 36, "width": 3400, "height": 2200, "maxEmpires": 5, "desc": "The standard galaxy." },

src/games/mastervega/VegaLeaders.js

@@ -3,7 +3,9 @@
 // A leader is hired once, costs upkeep forever, and does nothing at all until
 // posted. Admins run a colony; captains run a fleet. Headless.
 
-import { empireColonies, empireFleets, hireLeader, assignLeader, fleetPower } from './VegaLogic.js';
+import {
+  empireColonies, empireFleets, hireLeader, assignLeader, fleetPower, leaderHireCost,
+} from './VegaLogic.js';
 
 // Leaders are a shared galactic pool — once an empire hires Nyx Holt, nobody
 // else can. That makes the offer worth taking when it appears.
@@ -48,7 +50,7 @@ export function runLeaderTurn(rules, state, e) {
   const budget = emp.bc * 0.35;
   for (const offer of leaderOffers(rules, state, e)) {
     if (emp.leaders.length >= 6) break;
-    if (offer.hireCost > budget) continue;
+    if (leaderHireCost(rules, state, e, offer.id) > budget) continue;
     if (hireLeader(rules, state, e, offer.id)) break; // one hire per turn
   }
 

src/games/mastervega/VegaLogic.js

@@ -1967,14 +1967,29 @@ export function moveQueueRun(rules, state, colony, rows, ri, dir) {
   return true;
 }
 
+// A leader's list price (rules.leaders[id].hireCost) is fixed; what an
+// empire actually pays climbs with how many leaders it already has on
+// staff, so stockpiling BC and clearing the shared pool cheaply stops being
+// the dominant strategy once a roster gets going. The 1st hire is always
+// list price.
+export function leaderHireCost(rules, state, e, leaderId) {
+  const leader = rules.leaders[leaderId];
+  if (!leader) return Infinity;
+  const owned = state.empires[e].leaders.length;
+  return Math.round(leader.hireCost * (1 + owned * rules.leaderHiring.costScalePerOwned));
+}
+
 export function hireLeader(rules, state, e, leaderId) {
   const emp = state.empires[e];
   const leader = rules.leaders[leaderId];
   if (!leader || emp.leaders.some((l) => l.leaderId === leaderId)) return false;
-  if (emp.bc < leader.hireCost) return false;
+  const cost = leaderHireCost(rules, state, e, leaderId);
-  emp.bc -= leader.hireCost;
+  if (emp.bc < cost) return false;
+  emp.bc -= cost;
   emp.leaders.push({ leaderId, assignKind: null, assignId: -1 });
-  pushEvent(state, { type: 'leaderHired', empire: e, leaderId, turn: state.turn });
+  pushEvent(state, {
+    type: 'leaderHired', empire: e, leaderId, cost, turn: state.turn,
+  });
   return true;
 }
 
@@ -1994,6 +2009,15 @@ export function assignLeader(rules, state, e, leaderId, kind, id) {
   return true;
 }
 
+export function unassignLeader(rules, state, e, leaderId) {
+  const emp = state.empires[e];
+  const l = emp.leaders.find((x) => x.leaderId === leaderId);
+  if (!l || l.assignKind === null) return false;
+  l.assignKind = null;
+  l.assignId = -1;
+  return true;
+}
+
 // --------------------------------------------------------------------------
 // Serialisation
 

src/games/mastervega/VegaRules.js

@@ -18,6 +18,7 @@ export function compileRules(json) {
   need(json.combat && typeof json.combat === 'object', 'combat block missing');
   need(json.council && typeof json.council === 'object', 'council block missing');
   need(json.diplomacy && typeof json.diplomacy === 'object', 'diplomacy block missing');
+  need(json.leaderHiring && typeof json.leaderHiring === 'object', 'leaderHiring block missing');
   if (errors.length) throw new Error(`mastervega-rules invalid: ${errors.join('; ')}`);
 
   const byId = (list, label) => {
@@ -260,6 +261,7 @@ export function compileRules(json) {
     combat: json.combat,
     council: json.council,
     diplomacy: json.diplomacy,
+    leaderHiring: json.leaderHiring,
     victory: json.victory ?? { conquest: true, council: true, turnCap: 800 },
     starNames: json.starNames,
   };

src/games/mastervega/VegaScreens.js

@@ -7,7 +7,9 @@
 import * as Phaser from 'phaser';
 import { GAME_HEIGHT, GAME_WIDTH } from '../../config.js';
 import { Button } from '../../ui/Button.js';
-import { empireColonies, hireLeader } from './VegaLogic.js';
+import {
+  empireColonies, empireFleets, hireLeader, assignLeader, unassignLeader, leaderHireCost,
+} from './VegaLogic.js';
 import {
   attitudeOf, moodOf, powerOf, canNegotiate,
 } from './VegaDiplomacy.js';
@@ -252,6 +254,47 @@ export function openCouncilScreen(scene, rules, state, onClose) {
 
 // --------------------------------------------------------------------------
 
+/** "3× Cruiser, 2× Frigate (at Vega Prime)" / "(en route to Vega Prime)". */
+function fleetLabel(rules, state, f) {
+  const ships = f.ships.filter((s) => s.count > 0)
+    .map((s) => `${s.count}× ${rules.hulls[s.hullId]?.name}`).join(', ') || 'empty fleet';
+  const where = f.starIdx >= 0
+    ? `at ${state.galaxy.stars[f.starIdx]?.name}`
+    : `en route to ${state.galaxy.stars[f.toStar]?.name ?? '?'}`;
+  return `${ships} (${where})`;
+}
+
+/** A vertical list picker overlaid on `shell` — same mechanism as
+ * VegaAudience.js's pickFromList, generalised to any {label, onPick} list
+ * since this screen has no existing picker of its own. */
+function openListPicker(scene, shell, title, items) {
+  const bx = GAME_WIDTH / 2;
+  const by = GAME_HEIGHT / 2;
+  const box = scene.add.container(0, 0);
+  shell.add(box);
+  const h = Math.min(520, 100 + Math.max(items.length, 1) * 34);
+  box.add(scene.add.rectangle(bx, by, GAME_WIDTH, GAME_HEIGHT, 0x000000, 0.001).setOrigin(0.5).setInteractive());
+  box.add(scene.add.rectangle(bx, by, 460, h, PANEL, 0.98).setStrokeStyle(2, ACCENT));
+  box.add(scene.add.text(bx, by - h / 2 + 26, title, { fontFamily: FONT, fontSize: '19px', color: '#ffd88a' }).setOrigin(0.5));
+  if (!items.length) {
+    box.add(scene.add.text(bx, by, 'Nothing available.', {
+      fontFamily: FONT, fontSize: '15px', color: '#6f8aa3',
+    }).setOrigin(0.5));
+  }
+  items.slice(0, 12).forEach(([label, fn], i) => {
+    const t = scene.add.text(bx, by - h / 2 + 66 + i * 34, label, {
+      fontFamily: FONT, fontSize: '16px', color: '#e8f4ff',
+    }).setOrigin(0.5).setInteractive({ useHandCursor: true });
+    t.on('pointerover', () => t.setColor('#ffd88a'));
+    t.on('pointerout', () => t.setColor('#e8f4ff'));
+    t.on('pointerdown', () => { box.destroy(true); fn(); });
+    box.add(t);
+  });
+  const cancel = new Button(scene, bx, by + h / 2 - 34, 'Cancel', () => box.destroy(true),
+    { width: 160, height: 40, fontSize: 16, variant: 'ghost' });
+  box.add(cancel);
+}
+
 export function openLeaderScreen(scene, rules, state, e, art, onClose, onChanged) {
   const shell = modalShell(scene, 'Leaders', onClose, { width: 1180, height: 760 });
   const emp = state.empires[e];
@@ -261,7 +304,8 @@ export function openLeaderScreen(scene, rules, state, e, art, onClose, onChanged
   }));
   let y = shell.body.y + 34;
   for (const offer of leaderOffers(rules, state, e)) {
-    const affordable = emp.bc >= offer.hireCost;
+    const cost = leaderHireCost(rules, state, e, offer.id);
+    const affordable = emp.bc >= cost;
     shell.add(scene.add.image(shell.body.x + 32, y + 30, art.leaders, offer.portraitFrame)
       .setDisplaySize(60, 60));
     shell.add(scene.add.text(shell.body.x + 76, y + 4, `${offer.name} — ${offer.kind}`, {
@@ -275,7 +319,7 @@ export function openLeaderScreen(scene, rules, state, e, art, onClose, onChanged
         fontFamily: FONT, fontSize: '13px', color: '#7fd8a0',
       }));
     const b = new Button(scene, shell.body.x + shell.body.w - 130, y + 30,
-      `Hire ${offer.hireCost} BC`, () => {
+      `Hire ${cost} BC`, () => {
         if (hireLeader(rules, state, e, offer.id)) {
           shell.destroy();
           openLeaderScreen(scene, rules, state, e, art, onClose, onChanged);
@@ -298,18 +342,50 @@ export function openLeaderScreen(scene, rules, state, e, art, onClose, onChanged
   }
   for (const l of emp.leaders) {
     const def = rules.leaders[l.leaderId];
-    const posting = l.assignKind === 'colony'
+    let where = 'unassigned';
-      ? (empireColonies(state, e).find((c) => c.id === l.assignId)?.starIdx ?? -1)
+    if (l.assignKind === 'colony') {
-      : -1;
+      const c = empireColonies(state, e).find((c2) => c2.id === l.assignId);
-    const where = l.assignKind === 'colony' && posting >= 0
+      where = c ? `${c.name} (${state.galaxy.stars[c.starIdx]?.name})` : 'unassigned';
-      ? state.galaxy.stars[posting].name
+    } else if (l.assignKind === 'fleet') {
-      : (l.assignKind === 'fleet' ? `Fleet ${l.assignId}` : 'unassigned');
+      const f = empireFleets(state, e).find((f2) => f2.id === l.assignId);
+      where = f ? fleetLabel(rules, state, f) : 'unassigned';
+    }
     shell.add(scene.add.image(shell.body.x + 24, y + 18, art.leaders, def.portraitFrame)
       .setDisplaySize(40, 40));
     shell.add(scene.add.text(shell.body.x + 56, y + 6,
       `${def.name} — ${def.kind} — ${where} — ${def.upkeep} BC/turn`, {
         fontFamily: FONT, fontSize: '16px', color: '#c8dcf0',
+        wordWrap: { width: shell.body.w - 320 },
       }));
+
+    // Posting picker: admins list colonies, captains list fleets. Re-opens
+    // the whole screen on pick/unassign, same refresh pattern the Hire
+    // button already uses above.
+    const refresh = () => {
+      shell.destroy();
+      openLeaderScreen(scene, rules, state, e, art, onClose, onChanged);
+      onChanged?.();
+    };
+    const openPicker = () => {
+      const targets = def.kind === 'admin'
+        ? empireColonies(state, e).map((c) => [
+          `${c.name} (${state.galaxy.stars[c.starIdx]?.name})`,
+          () => { assignLeader(rules, state, e, l.leaderId, 'colony', c.id); refresh(); },
+        ])
+        : empireFleets(state, e).filter((f) => f.starIdx >= 0 || f.toStar >= 0).map((f) => [
+          fleetLabel(rules, state, f),
+          () => { assignLeader(rules, state, e, l.leaderId, 'fleet', f.id); refresh(); },
+        ]);
+      openListPicker(scene, shell, def.kind === 'admin' ? 'POST TO WHICH COLONY?' : 'POST TO WHICH FLEET?', targets);
+    };
+    shell.add(new Button(scene, shell.body.x + shell.body.w - 110, y + 20,
+      l.assignKind ? 'Reassign' : 'Assign', openPicker, { width: 118, height: 32, fontSize: 14 }));
+    if (l.assignKind) {
+      shell.add(new Button(scene, shell.body.x + shell.body.w - 250, y + 20, 'Unassign', () => {
+        unassignLeader(rules, state, e, l.leaderId);
+        refresh();
+      }, { width: 118, height: 32, fontSize: 14, variant: 'ghost' }));
+    }
     y += 44;
   }
   return shell;