ducoterra
35d65d2f25
Relax the phase-94 folder-summary scope rule from ≥ 2 documents to ≥ 1: a folder (or source root) is a candidate while ANY document lives under it, so single-file folders and single-file source roots get their own lite-written description. A row is now pruned only when its folder loses its last document (vanishes from the catalogue). The constant is the single source of truth, so the flip propagates to the generator's candidate set, the prune pass, the missing_folder_summaries gap probe (the next sync self-heals the new gaps), and the KB-tree summary_pending markers (1-doc folders / sources now read "Summary pending" until their row lands). Docstrings/comments across app/, scripts/import_docs.py, and the E2E fixtures updated to the ≥ 1 wording. Unit + integration tests updated to the new semantics (the pruned-below-minimum scenario is now a folder losing its LAST doc; single-doc folders are pinned as candidates/pending). Full suite: 2314 passed, app coverage 99%; ruff + pyright clean; folder-summary E2E stories pass in isolation (ls_tree_drilldown, sync_summary_visibility, kb_tree, kb_tree_nav, document_dates, oneshot_llm_retry).