RFD-087: Session-Scoped Active Workspace

[JeanMertz]

Tracking issue for RFD-087: Session-Scoped Active Workspace.

This issue tracks the progress towards the complete implementation of RFD-087.

Tasks

• Phase 1: Replace the storage symlink with the per-root registry directory (~/.local/share/jp/workspace/<id>/roots/<root-key>.json)
• Phase 1: Resolve -w <id> against the roots registry (one live root → use it; many → picker/error; none → error)
• Phase 1: Derive root liveness via the same-ID check (<root>/.jp/.id equals <id>)
• Phase 1: Seed the roots registry from any legacy storage symlink on first bootstrap
• Phase 2: Move session resolution ahead of workspace construction in jp_cli
• Phase 2: Add the jp_cli bootstrap step that selects the concrete checkout root
• Phase 2: Establish the workspace-root-as-child-cwd invariant for from-anywhere runs
• Phase 2: Add per-command workspace bootstrap requirement (none / resolve / load), analogous to conversation_load_request
• Phase 3: Add the user-global session store (~/.local/share/jp/sessions/<source-key>.json) with history-shaped records mirroring RFD 020
• Phase 3: Implement jp w use ? (picker), jp w use cwd (clear selection), jp w ls, and jp w show with the shared WorkspaceTarget grammar
• Phase 3: Implement jp q-from-anywhere resolution (global session → workspace root → per-workspace conversation → run)
• Phase 3: Implement source-split cleanup rules (getsid/Hwnd process-liveness; Env existence-based via workspace-ID liveness)
• Phase 4: Implement the interactive precedence ladder (explicit -w → sticky → conflict prompt → cwd → session-active → picker)
• Phase 4: Implement the cwd-vs-active conflict prompt (c/C/a/A/q)
• Phase 4: Implement persisted sticky (A) state on the session record and clearing via jp w use cwd
• Phase 4: Implement non-interactive mode rule (ignore session-active workspace; error without explicit -w or cwd workspace)
• Phase 4: Implement reprompt-on-missing-root (recover via stored workspace_id, expand roots registry, re-prompt among live checkouts)