Add docs slides and harden agent execution

[rschardosin]

Summary

• add the docs/slides domain, storage schemas, exporters, runtime components, and embedded frontend bundle support
• add generated personal/team Ent support for decks and slides
• make approved-plan dispatch asynchronous and retryable in the TUI
• enforce bounded graph-plan and delegated-agent research budgets
• restore approved PLAN.md state before execution and limit execution-time rediscovery
• include all pending tests, documentation, storage, authorization, and UI updates from the working tree

Verification

• git diff --check
• go test ./pkg/tui/... ./pkg/launcher/... ./pkg/agent/... ./pkg/session/... ./pkg/tools/...
• commit hook: golangci-lint v2.12.2 (0 issues)