0.2.0: feature-complete UI — 5 FTB-Library screens + HUD overlay

All five screens implemented with FTB Library widgets (Panel/Widget/
SimpleTextButton). Layout matches FTB Quests/Chunks for visual
consistency with the rest of the pack.

Screens:
- TierUpgradeScreen   — 13-row ladder, current tier highlighted,
                        Upgrade button to next tier with cost/affordability check
- ShopBrowserScreen   — 9-cell item grid + detail pane, quick-sell
                        buttons (1/16/64) with live DR-aware price preview
- BountyBoardScreen   — daily pool + active set, accept/cancel/turn-in
                        per state, slot-cap indicator
- PlotPurchaseScreen  — plot list + detail pane, buy/release with
                        ownership colour-coding and tier-gated buy
- QuestLogScreen      — at-a-glance tier+balance summary, active
                        bounties with progress bars, owned plots

HUD overlay: top-left tier name + spurs balance, registered as a
NeoForge GUI layer above the experience bar. 1Hz server push keeps
the balance current without polling client-side inventory.

Network: replaces single smoke-test packet with 7-packet contract:
- C2S: RequestEconomySnapshot, RunBnsCommand (whitelisted)
- S2C: TierStateUpdate, SellSnapshot, BountySnapshot, PlotSnapshot, Toast

Server-side bridge (ServerEconomyBridge) reads player NBT and
Numismatics-by-item-id-string for balance, routes write verbs
through the existing KubeJS /bns chat commands so KubeJS remains the
source of truth for economy logic.

Key bindings (rebindable in vanilla controls menu):
- K  Civic tier ladder
- J  Bounty board
- N  Plot office
- H  Bazaar shop
- M  Quest log

FTB Library + Architectury maven repos wired in build.gradle as
compileOnly; the jar stays small since FTB Library is already in pack.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

gradle.properties

@@ -19,5 +19,5 @@ loader_version_range=[1,)
 mod_id=bnstoolkit
 mod_name=Brass and Sigil Toolkit
 mod_license=All Rights Reserved
-mod_version=0.1.1
+mod_version=0.2.0
 mod_group_id=uk.sijbers.bnstoolkit