Add warning-mode block behavior with fresh blocked-tab reconciliation

[Copilot]

This adds a bypassable warning mode alongside the existing hard block flow, with a global default and per-filter overrides that preserve current behavior for existing and new users. It also treats blocked-page rendering as a tab-state reconciliation problem so tabs already sitting on the blocked page re-resolve correctly when rules change.

• Block-type configuration

  • Adds global Block Type storage/defaulting (Block Page or Warning)
  • Adds per-filter override support (Default, Block, Warning)
  • Keeps current behavior as the default for migrated and fresh installs

• Filtering and precedence

  • Extends block decisions to carry effective blockType
  • Resolves per-filter override vs global default in the filtering engine
  • Preserves existing allow precedence
  • When multiple filters match, hard block wins over warning; otherwise the applicable warning is used

• Blocked-tab state machine / reconciliation

  • Reworks blocked-page state resolution around fresh background-computed tab state
  • Stops relying on stale blocked-page URL params except as fallback/migration input
  • Handles transitions across allowed, hard-blocked, warning-blocked, and warning-bypassed
  • Ensures hard blocks override any prior warning bypass

• Warning bypass behavior

  • Adds blocked-page Continue for warning interstitials
  • Persists bypass state per tab session, scoped to the same warning filter and URL origin/fallback key
  • Temporary filters inherit the global block behavior unless later edited

• UI surfaces

  • Adds block-type controls in settings/modal flows only
  • Leaves popup and filter lists unchanged as requested
  • Updates blocked-page actions to show warning-specific behavior without changing hard-block behavior

• Tests

  • Adds/updates unit and e2e coverage for block-type normalization, precedence, warning bypass scope, and blocked-page state transitions, including hard-block → warning while already on the blocked page

const decision = evaluateFilterDecision(url, data);

if (decision.action === 'block') {
  // decision.blockType is 'block' | 'warning'
  // hard blocks take precedence over warnings
}