feat(cli): prompt in a GUI instead of the console, plus a global approval policy

CHANGELOG.md

@@ -7,6 +7,33 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+- **GUI prompts for value entry and release approval.** secretspec now prompts
+  for secret values and release approval in a GUI window instead of the
+  console/stdin, so a CI job or coding agent that only *triggers* a secret
+  operation never sees the value: the calling process cannot read or drive a
+  separate window. When `secretspec set` (or a `secretspec check` that fills a
+  missing secret) needs a value, it detects whether this machine can show a GUI
+  and uses it automatically, with nothing to opt into: a built-in dialog that
+  needs no external program (it grabs the keyboard on X11), falling back to a
+  `/dev/tty` terminal prompt when no display is available, and only then to stdin.
+  Set `require_approval` in `[project]` (`true`, `false`, or `"agents"`) to
+  require human approval at that same prompt before `secretspec run` injects
+  secrets into a command, `secretspec get` prints one, or `secretspec import`
+  copies them to another provider — and because the triggering tool cannot drive
+  the window, it cannot self-approve. Works with every provider. Note the GUI
+  prompt never reads a piped value: on a machine with a display, `echo v |
+  secretspec set KEY` opens a dialog rather than storing `v`. To set from a
+  script, pass the value inline (`secretspec set KEY "$V"`), which always wins.
+- **`require_approval` can be set once for every project**, as
+  `[defaults].require_approval` in `~/.config/secretspec/config.toml`, so you can ask
+  to be prompted whenever an agent releases secrets anywhere on your machine without
+  editing each `secretspec.toml`. The project and user policies are combined by
+  taking whichever is stricter (`false` < `"agents"` < `true`), so a project you
+  cloned cannot switch off the approval you configured for yourself, and you cannot
+  switch off the approval a project demands of every clone. `secretspec config show`
+  now prints the user-level policy.
+
 ## [0.13.0] - 2026-07-03
 
 ### Added