feat: make crosswalk and stop-line offsets solvable

Step 1 of the control-marking task, and deliberately server-only: no handle is
drawn yet. This project already shipped a range handle for `profile.interval`,
which compileGeometry ignores, so the control dragged and changed nothing. The
consumer comes first now.

Two kinds join the taxonomy — `junction-crosswalk-inset` and
`junction-stop-line-offset`, both on the existing `junction-approach` anchor. The
solver writes them onto the approach entry, `applyDirectJunctionPlans` carries
them onto the compiled approach, and `compileControlMarkings` reads them in place
of the module constants it used for every junction. They move markings without
reshaping the junction, so unlike width and cutback they deliberately do not
trigger a boundary recompute.

`applyJunctionConstraint` becomes an explicit switch. Its trailing `else` had
meant every kind that was not approach-width fell through to the cutback
validator, so a new kind would have been silently validated and written as a
cutback. The same non-exhaustive shape in the test fixture's `valueFor` is fixed
the same way, and now throws for an unnamed kind rather than answering with a
corner radius.

design.md's taxonomy is updated with it — a test asserts the two cannot drift,
which is what caught the omission.

Measured on a 41-road workspace with 8 crossings: both constraints change their
marking geometry, neither drags the other, and out-of-range blocks instead of
clamping. That measurement is not in the suite: the synthetic junction resolves
`junction_inset_m` to 0 because its crossing never binds to a plan, and the
committed OSM fixture has no crossings at all. The tests assert the wiring the
handles will depend on — values reaching the approach entry, distinct branches,
blocking diagnostics — and the gap is recorded in the test itself.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

.trellis/scripts/common/task_queue.py

@@ -0,0 +1,188 @@
+#!/usr/bin/env python3
+"""
+Task queue utility functions.
+
+Provides:
+    list_tasks_by_status   - List tasks by status
+    list_pending_tasks     - List tasks with pending status
+    list_tasks_by_assignee - List tasks by assignee
+    list_my_tasks          - List tasks assigned to current developer
+    get_task_stats         - Get P0/P1/P2/P3 counts
+"""
+
+from __future__ import annotations
+
+from pathlib import Path
+
+from .paths import (
+    get_repo_root,
+    get_developer,
+    get_tasks_dir,
+)
+from .tasks import iter_active_tasks
+
+
+# =============================================================================
+# Internal helper
+# =============================================================================
+
+def _task_to_dict(t) -> dict:
+    """Convert TaskInfo to the dict format callers expect."""
+    return {
+        "priority": t.priority,
+        "id": t.raw.get("id", ""),
+        "title": t.title,
+        "status": t.status,
+        "assignee": t.assignee or "-",
+        "dir": t.dir_name,
+        "children": list(t.children),
+        "parent": t.parent,
+    }
+
+
+# =============================================================================
+# Public Functions
+# =============================================================================
+
+def list_tasks_by_status(
+    filter_status: str | None = None,
+    repo_root: Path | None = None
+) -> list[dict]:
+    """List tasks by status.
+
+    Args:
+        filter_status: Optional status filter.
+        repo_root: Repository root path. Defaults to auto-detected.
+
+    Returns:
+        List of task info dicts with keys: priority, id, title, status, assignee.
+    """
+    if repo_root is None:
+        repo_root = get_repo_root()
+
+    tasks_dir = get_tasks_dir(repo_root)
+    results = []
+
+    for t in iter_active_tasks(tasks_dir):
+        if filter_status and t.status != filter_status:
+            continue
+        results.append(_task_to_dict(t))
+
+    return results
+
+
+def list_pending_tasks(repo_root: Path | None = None) -> list[dict]:
+    """List pending tasks.
+
+    Args:
+        repo_root: Repository root path. Defaults to auto-detected.
+
+    Returns:
+        List of task info dicts.
+    """
+    return list_tasks_by_status("planning", repo_root)
+
+
+def list_tasks_by_assignee(
+    assignee: str,
+    filter_status: str | None = None,
+    repo_root: Path | None = None
+) -> list[dict]:
+    """List tasks assigned to a specific developer.
+
+    Args:
+        assignee: Developer name.
+        filter_status: Optional status filter.
+        repo_root: Repository root path. Defaults to auto-detected.
+
+    Returns:
+        List of task info dicts.
+    """
+    if repo_root is None:
+        repo_root = get_repo_root()
+
+    tasks_dir = get_tasks_dir(repo_root)
+    results = []
+
+    for t in iter_active_tasks(tasks_dir):
+        if (t.assignee or "-") != assignee:
+            continue
+        if filter_status and t.status != filter_status:
+            continue
+        results.append(_task_to_dict(t))
+
+    return results
+
+
+def list_my_tasks(
+    filter_status: str | None = None,
+    repo_root: Path | None = None
+) -> list[dict]:
+    """List tasks assigned to current developer.
+
+    Args:
+        filter_status: Optional status filter.
+        repo_root: Repository root path. Defaults to auto-detected.
+
+    Returns:
+        List of task info dicts.
+
+    Raises:
+        ValueError: If developer not set.
+    """
+    if repo_root is None:
+        repo_root = get_repo_root()
+
+    developer = get_developer(repo_root)
+    if not developer:
+        raise ValueError("Developer not set")
+
+    return list_tasks_by_assignee(developer, filter_status, repo_root)
+
+
+def get_task_stats(repo_root: Path | None = None) -> dict[str, int]:
+    """Get task statistics.
+
+    Args:
+        repo_root: Repository root path. Defaults to auto-detected.
+
+    Returns:
+        Dict with keys: P0, P1, P2, P3, Total.
+    """
+    if repo_root is None:
+        repo_root = get_repo_root()
+
+    tasks_dir = get_tasks_dir(repo_root)
+    stats = {"P0": 0, "P1": 0, "P2": 0, "P3": 0, "Total": 0}
+
+    for t in iter_active_tasks(tasks_dir):
+        if t.priority in stats:
+            stats[t.priority] += 1
+        stats["Total"] += 1
+
+    return stats
+
+
+def format_task_stats(stats: dict[str, int]) -> str:
+    """Format task stats as string.
+
+    Args:
+        stats: Stats dict from get_task_stats.
+
+    Returns:
+        Formatted string like "P0:0 P1:1 P2:2 P3:0 Total:3".
+    """
+    return f"P0:{stats['P0']} P1:{stats['P1']} P2:{stats['P2']} P3:{stats['P3']} Total:{stats['Total']}"
+
+
+# =============================================================================
+# Main Entry (for testing)
+# =============================================================================
+
+if __name__ == "__main__":
+    stats = get_task_stats()
+    print(format_task_stats(stats))
+    print()
+    print("Pending tasks:")
+    for task in list_pending_tasks():
+        print(f"  {task['priority']}|{task['id']}|{task['title']}|{task['status']}|{task['assignee']}")