Fix re-issue for CNs whose issued cert file is missing

Renewal failed with an empty error box for any CN listed in index.txt
without a corresponding pki/issued/<CN>.crt — the state you get when an
index.txt is carried over from an older EasyRSA install but the issued/
files are not.

Two defects:

1. EasyRSA writes its diagnostics to stdout, not stderr: print() is
   `printf '%s\n'`, and both die() and user_error() route through it.
   stderr only carries output from the tools EasyRSA shells out to, and
   even that is silenced under -S/--silent-ssl. _run_easyrsa built its
   message from stderr alone, so every EasyRSA failure reported blank.
   _easyrsa_diagnostics() now merges both streams (stderr first, so the
   specific openssl message is not what the dialog clips) and drops the
   version banner and blank padding.

2. EasyRSA reads the serial out of the .crt itself, so revoke-issued
   cannot revoke a CN whose cert file is gone — and there is nothing to
   add to the CRL either. has_issued_cert() now gates the revoke and CRL
   steps in both CliRunner._issue() and CursesApp._process_cert(); the
   workflow warns and goes straight to build-client-full. An explicit
   --revoke / TUI `r` still fails loudly rather than silently no-op.

The post-build failure message now keys off whether a revoke actually
happened, not off is_renewal, so it no longer claims "has been revoked"
when nothing was.

Adds tests/test_app_reissue.py: the TUI re-issue path had no coverage at
all, and it is the path this bug was reported from.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

CLAUDE.md

@@ -53,7 +53,7 @@ python3 -m pytest tests/test_pki.py::test_sorted_ascending -v  # single test
 | SETTINGS OVERRIDE | `ConfigError`, `load_settings_overrides()`, `_OVERRIDABLE_SETTINGS` |
 | PKI | `CertInfo`, `_load_current_certs()`, `load_expiring_certs()`, `load_all_certs()`, `_parse_index_line()`, `get_email()` |
 | PASSWORD | `generate_password()` |
-| EASYRSA | `EasyRSAError`, `revoke_issued()`, `build_client_full()`, `gen_crl()`, `copy_crl()`, `is_ca_key_encrypted()`, `resolve_ca_passphrase()` |
+| EASYRSA | `EasyRSAError`, `_easyrsa_diagnostics()`, `issued_cert_path()`, `has_issued_cert()`, `revoke_issued()`, `build_client_full()`, `gen_crl()`, `copy_crl()`, `is_ca_key_encrypted()`, `resolve_ca_passphrase()` |
 | CONFIG | `build_ovpn()` → `vpn-configs/<CN>_<YYYY-MM-DD>_<NN>/CONFIG_NAME` |
 | CRYPTGEON | `CryptgeonError`, `create_note()` |
 | MAILER | `build_mime_message()`, `send_email()` |
@@ -66,6 +66,7 @@ python3 -m pytest tests/test_pki.py::test_sorted_ascending -v  # single test
 
 ## Re-issue workflow
 
+0. `has_issued_cert()` gates steps 1–2: if `<PKI_DIR>/issued/<CN>.crt` is absent, both are **skipped** with a warning and the workflow goes straight to step 3. EasyRSA reads the serial out of the `.crt` itself, so `revoke-issued` can only fail on such a CN — and there is nothing to add to the CRL either. This happens when an `index.txt` is carried over from an older EasyRSA install without the `issued/` files: the index still lists V-status certs whose `.crt` never came along. `--revoke` / the TUI `r` key deliberately do *not* skip — an explicit revoke request should fail loudly rather than silently no-op
 1. `revoke-issued <CN>` — archives old key + CSR to `pki/revoked/`
 2. CRL regenerated and copied to `CRL_DEST_PATH` immediately after the revoke succeeds — the old cert is already revoked at this point, so the published CRL would otherwise be stale until a separate manual regen. Not fatal: a failure here is reported but the workflow continues to step 3 (a new cert is more urgent than a fresh CRL, and "Regenerate CRL" / `--gen-crl` remain available to retry)
 3. `build-client-full <CN> --passout=pass:<pw>` — generates new key + cert
@@ -86,6 +87,7 @@ python3 -m pytest tests/test_pki.py::test_sorted_ascending -v  # single test
 - External config file (`load_settings_overrides()`, run once in `main()` right after arg parsing, before dispatch): resolution order is `--config PATH` > `CONFIG_PATH` setting > `<this-script-path>.conf` next to the script. The CLI flag or `CONFIG_PATH` make the path explicit — a missing file there is a fatal `ConfigError`; the default `<script>.conf` path is optional and silently skipped if absent. The file is executed as Python (same syntax as the `SETTINGS` block, so only run trusted files) and only names listed in `_OVERRIDABLE_SETTINGS` are applied — `CONFIG_PATH` itself is deliberately not overridable this way
 - Email: set `SMTP_HOST` to use smtplib (SMTP_TLS: `"starttls"`/`"ssl"`/`""`); leave empty to use `MAIL_BINARY`. Auth skipped when `SMTP_USER=""`
 - EasyRSA called with `--batch`; `--passin=pass:<passphrase>` omitted when the resolved passphrase is empty
+- EasyRSA error text arrives on **stdout**, not stderr: its `print()` is `printf '%s\n'`, and both `die()` and `user_error()` route through it. stderr only carries output from the tools EasyRSA shells out to (openssl), and even that is silenced under `-S/--silent-ssl` (not passed here). `_easyrsa_diagnostics()` therefore merges both streams — building an error from stderr alone reports failures as blank
 - CA passphrase resolution (`resolve_ca_passphrase()`, run once in `main()` right after arg parsing, before dispatch): `CA_PASSPHRASE=""` → auto-detect via `is_ca_key_encrypted()` (checks `<PKI_DIR>/private/ca.key` PEM header for `ENCRYPTED`) and prompt only if encrypted; `"!empty"` → never check/prompt, passphrase is `""`; `"!ask"` → always prompt, skip detection; any other value → used literally. `--list`/`--list-all` skip this resolution entirely since they only read `index.txt` and never touch the CA
 - Cryptgeon: matches the `occulto` browser client — `key=os.urandom(32)` used directly (no derivation) for AES-256-GCM; `contents` = `base64(b"AES-GCM") + "--" + base64(nonce) + "--" + base64(ciphertext)`; `meta` = JSON string `{"type": "text"}`; URL = `<base>/note/<id>#<key.hex()>`
 - `copy_crl()` does `chmod 644` after copy, then runs `RESTORECON_BINARY` (default `restorecon`) on the copied file — best-effort like `is_ca_key_encrypted()`: a missing/misconfigured binary is swallowed, not fatal. Set `RESTORECON_BINARY=""` to disable on non-SELinux systems