[jhermesn]

Summary

This PR introduces an "Endless" mode that allows players to solve random articles one after another without waiting for daily puzzles. The mode is browser-local, doesn't affect daily stats or streaks, and provides a continuous gameplay experience.

Key Changes

• New endless mode module (src/lib/endless.ts): Implements endlessPool() to determine available articles based on released seasons, and pickEndless() to select random articles while avoiding immediate repeats.

• Storage for endless rounds (src/lib/storage.ts): Added EndlessRound interface and functions loadEndlessRound() and saveEndlessRound() to persist the current endless round per corpus in browser storage.

• Mode navigation and UI (src/components/Game.astro):

  • Added "New article" button for starting the next endless round
  • Added mode toggle link to switch between Daily and Endless modes
  • Hid stats and sharing UI in endless mode (replaced with "New article" button)
  • Added navigation to switch endless mode across different corpora

• Main app logic (src/scripts/app.ts):

  • Detects endless mode via ?m=endless URL parameter
  • resolveEndlessRound() loads or creates a new endless round based on the daily pool
  • setUpModeNavigation() manages mode switching UI
  • Endless rounds are saved independently from daily game state
  • Stats are only recorded in daily mode
  • Previous puzzle navigation is hidden in endless mode
  • Meta display shows different text for endless vs. daily modes

• Internationalization: Added translations for "Endless", "Daily", and "New article" in English and Portuguese, plus updated how-to-play text explaining endless mode.

• Tests: Added comprehensive test suite for endlessPool() and pickEndless() functions, plus tests for endless round persistence in storage.

Implementation Details

• Endless mode uses the same daily pool calculation (endlessPool) to ensure articles are only available after their season starts
• The pickEndless() function prevents immediate article repeats by filtering out the current article when the pool has multiple options
• Endless rounds are stored per-corpus with a single key, so starting a new round automatically replaces the previous one
• URL structure: ?c={corpus}&m=endless for endless mode vs. ?c={corpus}&p={puzzle} for daily mode
• The mode toggle link dynamically updates based on current mode and corpus