Quests: escorts stay on the follower list, quest givers come back

Escorts lost their place on the hero's follower list after a load, so
quest checks like the one in "Furchtbares Verbrechen" failed; they are
added back once after loading (town NPCs that tag along briefly are left
out). Restarted quests stay available (flag 1), which their giver's dialog
and accepting them need. Quest givers are read from the quest scripts:
when a running quest's giver dies, the quest restarts and the giver is
spawned again at her start; an accepted quest without its giver is repaired
on load. Notes on the script format and opcodes in docs/quests.md.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

CMakeLists.txt

@@ -78,7 +78,9 @@ add_library(sacredK SHARED
     src/mods/mainmenu.cpp
     src/mods/mapreveal.cpp
     src/mods/questbook.cpp
+    src/mods/followers.cpp
     src/mods/questfail.cpp
+    src/mods/questgiver.cpp
     src/mods/questnpc.cpp
     src/mods/anticheat.cpp
     src/mods/loadingscreen.cpp