Rebuild roadmap and browser qualification

[vaheed]

What changed

• replaces docs/roadmap.md with a complete ordered 16-phase product roadmap
• preserves the existing production foundation and adds the agreed edge gateway, bounded cell inventory, multi-cell pools, Simple Anycast, Cache v2 with Gzip/Brotli, active-passive origin failover, and managed OWASP CRS direction
• adds a mandatory completion gate for implementation, unit/feature tests, real-runtime E2E, scale, failure/recovery, documentation, browser qualification, and release decision
• replaces docs/manual-browser-qualification.md with owner-run evidence requirements, current exact baseline checks, and non-speculative activation contracts for planned phases
• keeps Laravel out of DNS/HTTP traffic, preserves bounded cells and last-valid state, and forbids dynamic unbounded containers, custom rule languages, microservices, Kafka, and Kubernetes requirements

Validation

• compared the branch against main
• only the two requested documentation files changed
• browser qualification was not executed; this change only rewrites its owner-run contract
• code/runtime tests were not run because no executable code or infrastructure changed