refactor: add terminal output and forms package (#1124)

- `internal/terminal`: streams and the prompting policy, interactive forms (issue, PR, review, merge, milestone), editor / pager / browser launching, JSON and `--jq` output.
- An aligned table renderer and a record renderer for human output; both strip control and escape characters from server-supplied text so titles and bodies cannot inject terminal sequences.

Reviewed-on: https://gitea.com/gitea/tea/pulls/1124
Reviewed-by: TheFox0x7 <95654+thefox0x7@noreply.gitea.com>

internal/terminal/streams.go

@@ -0,0 +1,130 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package terminal
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+
+	"charm.land/huh/v2"
+	"gitea.dev/tea/internal/clierr"
+	"golang.org/x/term"
+)
+
+// Streams records injected IO and independently detected terminal capabilities.
+type Streams struct {
+	In     io.Reader
+	Out    io.Writer
+	ErrOut io.Writer
+	InTTY  bool
+	OutTTY bool
+	ErrTTY bool
+}
+
+// System binds streams to the current process and detects each terminal.
+func System() Streams {
+	return Streams{In: os.Stdin, Out: os.Stdout, ErrOut: os.Stderr, InTTY: term.IsTerminal(int(os.Stdin.Fd())), OutTTY: term.IsTerminal(int(os.Stdout.Fd())), ErrTTY: term.IsTerminal(int(os.Stderr.Fd()))}
+}
+
+// Policy controls input interaction independently of supplied flag count.
+type Policy struct{ Enabled, NoInput, Machine, Interactive bool }
+
+// CanPrompt requires terminal input and diagnostics, without requiring terminal stdout.
+func (p Policy) CanPrompt(s Streams) bool {
+	return p.Enabled && !p.NoInput && (!p.Machine || p.Interactive) && s.InTTY && s.ErrTTY
+}
+
+// Validate rejects an explicit interactive request incompatible with terminal policy.
+func (p Policy) Validate(s Streams) error {
+	if p.Interactive && !p.CanPrompt(s) {
+		return clierr.Wrap(clierr.Usage, errors.New("--interactive requires terminal stdin/stderr, enabled prompting, and no --no-input"))
+	}
+	return nil
+}
+
+// Prompter abstracts cancellable input collection and confirmation.
+type Prompter interface {
+	Input(context.Context, string) (string, error)
+	SecretInput(context.Context, string) (string, error)
+	Confirm(context.Context, string) (bool, error)
+}
+
+// FormPrompter uses cancellable terminal forms with explicitly injected streams.
+type FormPrompter struct{ Streams Streams }
+
+func promptError(ctx context.Context, err error) error {
+	if ctx.Err() != nil {
+		return ctx.Err()
+	}
+	if errors.Is(err, huh.ErrUserAborted) {
+		return clierr.Wrap(clierr.Canceled, errors.New("input canceled"))
+	}
+	return err
+}
+
+func (p *FormPrompter) runForm(ctx context.Context, form *huh.Form) error {
+	return promptError(ctx, form.WithInput(p.Streams.In).WithOutput(p.Streams.ErrOut).RunWithContext(ctx))
+}
+
+// Input collects one field using the configured terminal streams.
+func (p *FormPrompter) Input(ctx context.Context, title string) (string, error) {
+	var value string
+	err := p.runForm(ctx, huh.NewForm(huh.NewGroup(huh.NewInput().Title(title).Value(&value))))
+	return strings.TrimSpace(value), err
+}
+
+// SecretInput collects a value without displaying it on the terminal.
+func (p *FormPrompter) SecretInput(ctx context.Context, title string) (string, error) {
+	var value string
+	err := p.runForm(ctx, huh.NewForm(huh.NewGroup(huh.NewInput().Title(title).EchoMode(huh.EchoModePassword).Value(&value))))
+	return value, err
+}
+
+// Confirm collects a yes/no choice through cancellable terminal input.
+func (p *FormPrompter) Confirm(ctx context.Context, title string) (bool, error) {
+	var accepted bool
+	err := p.runForm(ctx, huh.NewForm(huh.NewGroup(huh.NewConfirm().Title(title).Value(&accepted))))
+	return accepted, err
+}
+
+// Require fills missing input or returns an actionable usage error.
+func Require(ctx context.Context, value *string, flag string, streams Streams, policy Policy, prompt Prompter) (bool, error) {
+	if *value != "" {
+		return false, nil
+	}
+	if !policy.CanPrompt(streams) {
+		return false, clierr.Wrap(clierr.Usage, fmt.Errorf("missing required input: supply --%s", flag))
+	}
+	entered, err := prompt.Input(ctx, flag)
+	if err != nil {
+		return false, err
+	}
+	if entered == "" {
+		return false, clierr.Wrap(clierr.Usage, fmt.Errorf("--%s cannot be empty", flag))
+	}
+	*value = entered
+	return true, nil
+}
+
+// Confirm requires explicit acceptance unless confirmation was supplied by flag.
+func Confirm(ctx context.Context, description string, yes bool, streams Streams, policy Policy, prompt Prompter) error {
+	if yes {
+		return nil
+	}
+	if !policy.CanPrompt(streams) {
+		return clierr.Wrap(clierr.Usage, errors.New("confirmation required: supply --yes"))
+	}
+	accepted, err := prompt.Confirm(ctx, description)
+	if err != nil {
+		return err
+	}
+	if !accepted {
+		return clierr.Wrap(clierr.Canceled, errors.New("operation canceled"))
+	}
+	return nil
+}