docs: rewrite all READMEs for v0.30.0 — growth-optimized, feature-complete

Rewrites the English README and all 10 translations to reflect the
current state at v0.30.0. Major additions: On-Device AI, Multi-Session
Chat (dockview tabs), Developer Mode, System Monitor, Hook Events,
Session Source Badges, FSM architecture, Enterprise support, and the
plugin expansion from 8→86 MCP tools and 3→9 skills.

Structure redesigned for conversion: pain-first hook, install CTA above
the fold, features organized by user job, comparison table with new
columns, structured FAQ for AI citability.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: tombelieber