feat(tui): paste support in wizard inputs (F8)

[danielxxomg]

Summary

Tier 3 (final) of the tui-personality SDD change: bracketed-paste support in wizard text inputs (F8).

The wizard profile-name step now accepts tea.PasteMsg (v2 bracketed paste) and appends msg.Content to the active input buffer, so users can paste multi-character names/paths instead of typing rune-by-rune. Plain keystrokes continue to work alongside paste.

Changes

• internal/tui/screens/wizard.go: add case tea.PasteMsg: in Update, appending msg.Content to m.NameInput on the free-text StepName step (no-op on other steps so selection state is not corrupted).
• internal/tui/screens/wizard_test.go: table-driven paste tests (empty/non-empty input, spaces, path separators), paste-then-backspace, and no-op-on-non-name-step invariant.

Stacked chain note

This is the Tier 3 slice of a stacked-to-main chain:

• feat(tui): TUI personality — Tier 1 (window title, spinner indicators, status bar, gradient logo) #44 (Tier 1) → feat(tui): viewport dry-run + mouse nav + styled empty states (Tier 2) #45 (Tier 2) → this PR (Tier 3)

Branched from feat/tui-personality-tier2; the diff shrinks to the ~30-line Tier 3 slice once #44 and #45 merge to main. Tier 3 is functionally independent — paste only touches wizard.go Update, non-overlapping with Tier 1 window-title (View) work.

Verification

• go test ./internal/tui/screens/... ✅
• go test -cover ./internal/tui/screens/... → 85.1% (≥80%) ✅
• go vet ./... clean ✅
• golangci-lint run 0 issues ✅
• GGA pre-commit: PASSED ✅

Spec: openspec/changes/tui-personality/specs/wizard-flow/spec.md (F8 paste). SDD tasks Phase 5 marked complete.