Obsidian Eclipse

Everything is authored at the *exact* native pixel geometry of the vanilla 26.3
client, so the pack scales cleanly at every GUI scale setting with zero layout
drift. No `.mcmeta` sidecars are required – all nine-slice and animation rules
fall back to the vanilla defaults.

## What it changes

| Area | Result |
| — | — |
| Container screens | Brushed-obsidian panels with recessed slots and neon dividers, covering the survival inventory, chests (`generic_54`), crafting table, furnace / smoker / blast furnace, enchanting table, anvil, smithing, brewing stand, hopper, dispenser, shulker box, loom, cartography table, stonecutter, crafter, beacon, horse, villager and the creative item tabs |
| HUD | Minimalist hearts, hunger, armour, air, XP and jump bars with smooth gradient fills, plus a redesigned hotbar, selection frame and off-hand slots |
| Crosshair | Precision neon reticle with a matching attack-cooldown indicator (both the radial ring and the hotbar bar) |
| Menus & widgets | Dark-mode buttons, sliders, text fields, checkboxes, tabs, scrollbars, tooltips, popups, ping icons, notification dots and the title / pause menu backgrounds |
| Typography | A slimmer, higher-contrast re-authored bitmap font for dense reading of item names and code |
| Pack icon | `pack.png`, an obsidian plate with a neon eclipse |