fix(ssh): unlock passphrase-protected identity files

[sisodiahs]

Summary

• Prompt once when an identity file is encrypted, cache the passphrase in process memory, and retry SSH without waiting out reconnect backoff.
• Works in the TUI and desktop GUI; the host Password field stays the login password.

Fixes #97

Test plan

• Encrypted Ed25519 key, empty agent → prompt → connect succeeds; no second prompt
• Wrong passphrase → error, prompt stays
• hosts.toml never stores the passphrase
• ssh-add then connect with no prompt

[timhartmann7]

Thanks for this - and sorry for the slow reply

The feature itself looks well built. The typed AuthOutcome::PassphraseRequired instead of prompting from inside authenticate(), the non-blocking CoreEvent::KeyPassphraseRequired so the metrics poller never pops a dialog, the in-memory-only passphrase store, and the spawn_blocking around load_secret_key are all the right calls. Tests and CHANGELOG/README entries are there too.

The problem is that the diff is unreviewable as pushed: 220 files, +37k/-36k. Almost all of it is mechanical noise from two git settings on your side:

git diff --shortstat main...pr-103 -> 220 files, +37347 / -36507
git diff --shortstat -w main...pr-103 -> 220 files, +912 / -72

• 196 files were rewritten LF → CRLF
• 215 files flipped mode 100644 → 100755 (this is why 17 icon files with
  identical content show up as changed)

Could you re-push with:

git config core.fileMode false
git config core.autocrlf input

and a branch rebuilt on top of current main? That should land as roughly +912/-72 across ~35 files, which I can review properly

[sisodiahs]

Rebuilt the branch on current main and re-pushed. The noise should be gone now.

Diff is 35 files, +923/−83. Sorry about the review mess — should be readable now.