Research in the library: rooms, spells, towers, traps and doors are discovered in a fixed order

- studying creatures collect research points (mages and owls best, higher levels faster); studying gives less mana than before
- free play starts with the basics; campaign missions know what their story allows and can research what the next four missions would bring
- research shown in the top bar; the library's info lists the current item and what comes next; locked tools say whether they can be researched

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

lang/de.lang

@@ -789,3 +789,11 @@ best.b.frost.text = Kälte macht Helden langsam, und langsame Helden sind leicht
 best.b.door_wood.text = Hält Zugluft und Ritter draußen - eine Weile.
 best.b.door_iron.text = Schwer, genietet, stur. Bringt einen Rammbock mit, Helden.
 best.b.door_magic.text = Schlag zu, und sie schlägt zurück. Verschlossen ist sie das Ende jedes Ganges.
+
+# research
+hud.research = Forschung
+research.now = Erforscht: {0} ({1}%)
+research.next = danach: {0}
+research.done = Hier gibt es nichts mehr zu erforschen.
+msg.researched = Erforscht: {0}! Jetzt im Baumenü.
+msg.tool_research = Noch nicht erforscht - Kreaturen in der Bibliothek arbeiten daran.

lang/en.lang

@@ -790,3 +790,11 @@ best.b.frost.text = Cold makes heroes slow, and slow heroes make easy targets.
 best.b.door_wood.text = Keeps the draught and the knights out - for a while.
 best.b.door_iron.text = Heavy, riveted, stubborn. Bring a battering ram, heroes.
 best.b.door_magic.text = Strike it and it strikes back. Locked, it is the end of every corridor.
+
+# research
+hud.research = Research
+research.now = Researching: {0} ({1}%)
+research.next = then: {0}
+research.done = Nothing left to research here.
+msg.researched = Researched: {0}! It is in the build menu now.
+msg.tool_research = Not researched yet - creatures studying in the library work on it.