chore: community feedback fixes and UI improvements (#102)

## Summary

Addresses all community feedback tickets from the last deploy, plus several UI improvements made during the same session.

### Bug fixes & balance
- **#97** — Fix auto-adventurer tier priority: sort by combat power instead of current cost so the highest-tier affordable unit is always purchased
- **#98** — Add Dark Templar adventurer (80k CP) to bridge the Volcanic Depths progression wall; rewire upgrade and quest rewards accordingly
- **#99** — Reorder and buff Shadow Assassin (55k CP, level 12) so Witch Coven feels rewarding rather than a regression
- **#100** — Display effective Gold/s (all multipliers applied) in the resource bar
- **#101** — Add Peasant tier 2 (10x, essence) and tier 3 (50x, crystals) upgrades for meaningful late-game scaling

### Other fixes
- Sync game state to server before auto-boss challenges (matching manual challenge behaviour)
- Refresh Discord avatar hash on every game load via bot token so stale CDN URLs are corrected automatically

### UI improvements
- Replace Donate / Discord / Support / View Profile / Edit Profile buttons with a single avatar dropdown menu
- Collapse all resources except Gold into a click-to-toggle dropdown; orange alert dot appears when a hidden resource is capped

## Closes

Closes #97
Closes #98
Closes #99
Closes #100
Closes #101

Reviewed-on: #102
Co-authored-by: Hikari <hikari@nhcarrigan.com>
Co-committed-by: Hikari <hikari@nhcarrigan.com>

apps/api/src/data/bosses.ts

@@ -245,7 +245,7 @@ export const defaultBosses: Array<Boss> = [
     name:                "The Ancient Fire Elemental",
     prestigeRequirement: 0,
     status:              "locked",
-    upgradeRewards:      [ "celestial_guard_1" ],
+    upgradeRewards:      [ "dark_templar_1" ],
     zoneId:              "volcanic_depths",
   },
   {
@@ -263,7 +263,7 @@ export const defaultBosses: Array<Boss> = [
     name:                "The Magma Titan",
     prestigeRequirement: 0,
     status:              "locked",
-    upgradeRewards:      [ "crystal_resonance" ],
+    upgradeRewards:      [ "crystal_resonance", "celestial_guard_1" ],
     zoneId:              "volcanic_depths",
   },
   {