D35 — Configurator: opt-in interactive TUI (--tui)

Decision. The cmd/configure binary gains an interactive TUI mode activated by --tui, based on github.com/charmbracelet/bubbletea (+ bubbles, lipgloss). The generation business logic (Emit/Apply MCP config + provisioning.BuildManifest/Apply for skills) was extracted into a shared function runConfigure(configureParams); both the flag mode (default, unchanged) and the TUI call it. The wizard collects KB/provider/transport/URL/auth/token-env/name/base-dir/dry-run with defaults from DefaultConfig() and a confirmation screen.

Rationale. AD4 called for the TUI only in the multi-provider configurator (never in the server): this decision implements it. The key condition is zero duplication: the TUI is a pure front-end that populates the same parameters as the flags and delegates to runConfigure, so the two modes cannot diverge. Flags remain the default (the TUI is opt-in) → no regression for scripted/CI uses. bubbletea is the idiomatic TUI library in Go and is pure-Go (no cgo). It adds transitive dependencies (lipgloss/bubbles/x), acceptable for an administrative binary separate from the server.

(Superseded by D37: cmd/configure was deleted and the TUI recast as the flag-less dashboard of cartographer — --tui no longer exists, see docs/configurator.md §TUI mode.)