[rmkr-dev]

New game at games/forge/. Tap a number, a sign, then a second number to merge them into the result; make any tile equal the target.

• Journey: 15 puzzles over 5 tiers. Tiles grow from 3 to 5, × unlocks at tier 3 and ÷ at tier 5. Three skips.
• Blitz: 2 minutes, +5s per solve, -10s per skip, harder every 3 solves.
• Puzzles are built by playing legal steps forward, so every one is solvable. Par is the shortest route from a small solver, which also powers Hint (works from the current tiles) and shows one way after a skip.
• Scoring: tier base, par bonus, speed bonus in Journey, clean-streak bonus up to +50%, hints halve the puzzle's points.
• Undo, reset, pause (auto-pauses when the tab is hidden), results summary at the end of a run, keyboard controls.
• Best score per mode: rmkr-game-forge-best-journey and rmkr-game-forge-best-blitz.
• Uses the game-page tap handling from Unlist Casual Quiz and fix mobile taps on games #63. New styles are scoped under nf- in site.css.

Hub card and README entry added; home and nav unchanged.