Filter system overhaul

Filters are only useful if they're fast to set and easy to reuse.

The filter system is rebuilt. The old version worked but didn't persist — you'd configure a filter, use it once, and lose it. The new version is named, saved, and composable.

Saved presets: name a filter configuration and load it with a single command. /hot my-setup applies it instantly. Multiple presets for different strategies.

Mini App widget: full UI for building filters without typing. Sliders for holder count, volume thresholds, bonding curve range, sniper protection, price direction. Save as a named preset. Opens inside Telegram.

Inline power syntax: still there for speed. /hot 5m min_holders:50 max_sniper_pct:3 — chain as many parameters as you want. One-shot overrides don't affect saved presets.

Tier-based limits are properly enforced. Free gets the core filters. Premium and Pro unlock deeper controls and more saved slots.