add Python stopgap planning tooling under tools/scripts/plan

Ports settled-reach's decisions_sync.py + ticket + decision scripts,
Scrum-stripped. Writes to .pql/pql.db (gitignored). Verb shape
mirrors the eventual `pql` subcommands so migration is a call-site
find-replace once pql ships feature parity (D-040, R-011).

Ticket IDs are T-NNN (TEXT PKs) — reshape from settled-reach's
integer auto-increment so the stopgap's writes are compatible with
pql's future reads without a data migration. No `sprints` table; the
pyramid is kanban / waterfall (D-035).

Verified end-to-end: sync parses 71 records (39 confirmed, 23 open
questions, 9 rejected) with 62 cross-refs and zero broken links;
`ticket new`, `ticket status`, `ticket board`, and `decisions show
--with-refs` all round-trip correctly.

Co-Authored-By: Claude <noreply@anthropic.com>

tools/scripts/planning/db.py

@@ -0,0 +1,34 @@
+"""SQLite wrapper — opens `.pql/pql.db` at the repo root, applies schema.
+
+Discovery: walk up from CWD looking for a .git/ sibling; the repo root
+hosts .pql/pql.db. If .pql/ doesn't exist, it's created on first open.
+"""
+from __future__ import annotations
+
+import sqlite3
+from pathlib import Path
+
+from .schema import SCHEMA_SQL
+
+
+def repo_root(start: Path | None = None) -> Path:
+    path = (start or Path.cwd()).resolve()
+    for parent in (path, *path.parents):
+        if (parent / ".git").exists():
+            return parent
+    raise RuntimeError(f"not inside a git repository (starting from {path})")
+
+
+def db_path(root: Path | None = None) -> Path:
+    root = root or repo_root()
+    return root / ".pql" / "pql.db"
+
+
+def connect(root: Path | None = None) -> sqlite3.Connection:
+    path = db_path(root)
+    path.parent.mkdir(parents=True, exist_ok=True)
+    conn = sqlite3.connect(path)
+    conn.row_factory = sqlite3.Row
+    conn.execute("PRAGMA foreign_keys=ON")
+    conn.executescript(SCHEMA_SQL)
+    return conn