the documented way to use this did not work

`import qs.horologion.modules` was the README's headline instruction and it
fails outright: Quickshell resolves `qs` against the host config root, not
the subtree, so in an empty shell the type is unavailable and in a populated
one the widget would have silently bound to the host's Config and Theme
instead of its own. The imports inside are now relative and each directory
carries a qmldir, so `import "horologion/modules"` works in any host and the
three pieces really are usable on their own.

  - refresh() dropped a request made while a run was in flight, so a
    jurisdiction or date set a moment after startup never took effect until
    midnight. It queues now.
  - The waybar script exited non-zero on its error paths, and waybar hides a
    module whose script does that -- so a missing typikon made the module
    vanish rather than say so, and the .error CSS was dead. An unrecognised
    --format field raised instead of rendering empty, and the tooltip
    interpolated unescaped text into Pango markup, which matters because
    --update-menaion fetches commemorations from a page nobody here controls.
  - The installer aborted the whole run at the point where it printed
    'leaving it alone', and a wholly successful run exited 1 because the last
    statement was a failed [ -d ] test under set -e. --help demanded typikon,
    which is what --help would have told you to install.
  - eww painted every day with the feast colour and printed a dangling
    separator, because it compares against "" and eww renders a JSON null as
    the string "null". The parenthesised ?: form two lines away was already
    right. The week list also repeated today.

pip install typikon installed nothing; there is no such package, and that was
the first line of every install path. Pascha now carries its label instead of
being a bare ISO date in a corner.

tests/smoke.sh covers the scripts, which is where all of this lived and where
nothing was covered. It caught two of these while being written.

bin/horologion-waybar

@@ -14,6 +14,8 @@ particular law actually binds.
 """
 
 import argparse
+import collections
+import html
 import json
 import subprocess
 import sys
@@ -41,26 +43,42 @@ def main():
     try:
         days = run(args.jurisdiction, args.days)
     except FileNotFoundError:
+        # Exit 0 on purpose, here and below: waybar hides a custom module whose
+        # script exits non-zero, so a non-zero exit would make the module
+        # vanish instead of showing why it could not answer.
         print(json.dumps({"text": "typikon?", "tooltip":
                           "typikon is not on PATH", "class": "error"}))
-        return 1
+        return 0
     except (subprocess.CalledProcessError, ValueError) as exc:
         print(json.dumps({"text": "⚠", "tooltip": str(exc), "class": "error"}))
-        return 1
+        return 0
 
     today = days[0]
-    fields = dict(today)
+    # `or ""` would blank a legitimate 0, so only None and missing become "".
+    fields = {k: ("" if v is None else v) for k, v in today.items()}
     if args.no_emoji:
         fields["emoji"] = ""
-    text = args.format.format(**{k: fields.get(k) or "" for k in fields}).strip()
+    try:
+        # format_map over a defaultdict: a field name that does not exist comes
+        # out empty rather than raising, because the --help text advertises
+        # eight names and someone will always try a ninth.
+        text = args.format.format_map(collections.defaultdict(str, fields)).strip()
+    except (IndexError, ValueError) as exc:
+        print(json.dumps({"text": "\u26a0", "class": "error",
+                          "tooltip": f"bad --format: {exc}"}))
+        return 0
 
     tip = []
     head = today["title"]
     if today.get("churchDate") and today["churchDate"] not in head:
         head += f"   ({today['churchDate']})"
-    tip.append(f"<b>{head}</b>")
+    # waybar renders the tooltip as Pango markup, so anything interpolated into
+    # it has to be escaped. Nothing in the shipped data contains an ampersand,
+    # but `typikon --update-menaion` fetches commemorations from a third-party
+    # page, and that is exactly where one arrives.
+    tip.append(f"<b>{html.escape(head)}</b>")
     if today.get("cycle"):
-        tip.append(f"<i>{today['cycle']}</i>")
+        tip.append(f"<i>{html.escape(today['cycle'])}</i>")
     tip.append("")
     line = today["fastLabel"]
     if today.get("obligation") == "obligatory":