fix: preserve remote session identity across session restore paths

[wsp1911]

Summary

Preserve remote workspace identity across session-targeted agent flows and restore paths, and shorten generated cron job ids.

Fixes #

Type and Areas

Type:

bug fix / regression fix

Areas:

Rust core, desktop/Tauri, CLI, runtime ports, remote connect, cron, web UI tests

Motivation / Impact

Remote sessions could lose their SSH identity when restored, queued, or triggered through some internal paths, causing session history, cron/session tools, /init, manual compaction, fork context capture, remote dialog turns, or scheduled jobs to resolve against the wrong local/slugged storage path.

This PR makes remote session identity explicit across session workspace bindings, scheduler submissions, cron/session tools, remote dialog submissions, and persistence/session listing paths. It separates logical workspace paths from final on-disk session storage directories: remote sessions restore from resolved session storage paths, while tools/UI continue to receive logical workspace paths.

It also adds explicit restore APIs for three different inputs:

• logical workspace path plus remote identity
• already resolved session storage directory
• legacy/local workspace path

This avoids passing a resolved sessions directory through APIs named workspace_path, which previously caused double path resolution.

Generated cron job ids are now shorter (cron_ + 8 lowercase hex chars) while still checking existing jobs and retrying on collision.

Verification

• pnpm run fmt:rs
• cargo test -p bitfun-core workspace_identity_ -- --nocapture
• cargo test -p bitfun-core restore_session_ -- --nocapture
• cargo test -p bitfun-core restore_session_for_workspace_uses_remote_identity -- --nocapture
• cargo test -p bitfun-core generate_cron_job_id_uses_short_hex_suffix -- --nocapture
• cargo check -p bitfun-core
• cargo check -p bitfun-desktop
• pnpm --dir src/web-ui run test:run src/app/startup/startupPerformanceContract.test.ts
• git diff --check

Reviewer Notes

The main compatibility-sensitive change is the distinction between logical workspace paths and final on-disk session storage directories. Remote workspaces should continue to expose remote logical paths to tools/UI, but persistence and restore paths should use the resolved SSH mirror session directory.

Restore APIs are now intentionally split by input type. Callers that already have a resolved sessions directory should use the storage-path restore APIs. Callers with a logical workspace and remote identity should use the workspace request APIs. Bare Path restore methods remain for local/legacy callers only.

Unresolved remote sessions intentionally stay under the dedicated unresolved remote session tree instead of falling back to local project slug storage.

Cron job ids are intentionally shortened for readability. Creation remains collision-safe through an existing-job check and retry loop.

Checklist

• This PR is focused and does not include secrets, temporary prompts, generated scratch files, or unrelated artifacts.
• Relevant verification is recorded above, or skipped checks are explained.
• User-facing strings, docs, and locales are updated where applicable.