A stash is a side-channel from history: it holds drafts the user
parked deliberately instead of submissions made in the past
(which live in `composer_history.rs`).
* `crates/tui/src/composer_stash.rs` — JSONL-backed store at
`~/.deepseek/composer_stash.jsonl`. One JSON object per line
with `ts` (RFC 3339) and `text`. Self-healing parser drops
malformed lines instead of poisoning the file. Multi-line
drafts round-trip intact via JSON's newline escaping. Capped
at 200 entries; oldest pruned at push time. Empty /
whitespace-only text is silently dropped.
* `crates/tui/src/commands/stash.rs` — `/stash list` renders the
stash with one-line previews and timestamps; `/stash pop`
restores the most recently parked draft into the composer
(LIFO) and rewrites the file. `/park` aliases `/stash`.
* Composer Ctrl+S handler in `tui/ui.rs` — pushes the current
draft onto the stash, clears the composer, and surfaces a
toast confirming the action so the no-op-feel doesn't fool
users into thinking nothing happened. Empty composers are a
no-op so a stray Ctrl+S can't pollute the file.
* New `KbStashDraft` keybinding entry registered in the help
overlay; localized in en, ja, zh-Hans, pt-BR.
Tests:
7 unit tests in `composer_stash.rs` cover round-trip, LIFO pop,
empty-on-pop, drop-empty-text, multi-line preservation,
malformed-line resilience, and cap pruning. 4 unit tests in
`commands/stash.rs` cover the preview helper's truncation,
multi-line first-line behavior, and empty-input handling.
Hunter Bown
6fb8739feb