* feat(web): persist composer draft across session switches
Switching between sessions now preserves the text typed in the
composer. Drafts are stored per-session in sessionStorage and
restored when the user navigates back.
- Add composer-drafts utility (sessionStorage, in-memory cache)
- Restore draft on HappyComposer mount, save on unmount
- Clear draft on message send
- Evict oldest drafts when exceeding 50 entries
- Add unit tests for composer-drafts
Fixes#231
* fix(web): add key prop to HappyComposer for explicit remount on session switch
* fix(web): move clearDraft to SessionChat after send validation
Prevents draft loss when Codex rejects an unsupported slash command.
* fix(web): remove explicit clearDraft, rely on unmount save
Successful sends clear the composer text, so the unmount save
naturally persists an empty string which deletes the draft entry.
This avoids clearing the draft when the send is blocked or fails.
* fix(web): clear draft on successful send via onSuccess callback
Move draft clearing to the send-success path so drafts are only
removed after the message is actually accepted by the server.
* fix(web): pass session ID to onSuccess to clear correct draft
The previous version used the current route's sessionId, which could
clear the wrong draft if the user switched sessions before the send
completed.
* test(web): add useSendMessage onSuccess callback tests
Verify that onSuccess receives the correct session ID (including
resolved IDs), and is not called on send failure or block.
* refactor(web): extract useComposerDraft hook with unit tests
Extract the draft save/restore logic from HappyComposer into a
dedicated useComposerDraft hook. Adds 6 unit tests covering:
- mount: restores saved draft via rAF
- mount: skips restore if composer already has text
- mount: skips restore if no saved draft
- unmount: saves current text after rAF has fired
- unmount: skips save before rAF (draftReady guard)
- no-op when sessionId is undefined
* fix(web): clear both route and resolved session drafts after send
When resolveSessionId swaps the session (e.g. inactive → resumed),
the sent ID differs from the route's session ID. Extract
clearDraftsAfterSend so both are cleared and unit-testable.
* fix(web): refresh eviction order when updating an existing draft
Delete the key before re-inserting so Object.keys() reflects the
most recent write, preventing a recently edited draft from being
evicted first.
