fix(notify): group counters instead of padding columns

Pushover renders the notification body in a proportional font, so the
space-padded label/value columns never lined up on a phone — the body
collapsed into a ragged flat list with no visual grouping. The html
variant was worse: the padding sat inside the HTML, so it collapsed to a
single space.

Counters are now grouped two per line and joined with a middle dot, which
survives any font. The body drops from 8 lines to 5 and no longer restates
the outcome the title already carries.

- replace _notify_row/LABEL_WIDTH/VALUE_WIDTH with _stat_row
- add docs/notify-preview.py, which renders the real build_summary()
  output as a phone-width PNG so layout changes can be reviewed visually
- tests: assert no space padding, two counters per row, and that the body
  does not repeat the title

README.md

@@ -137,35 +137,46 @@ Pushover and Apprise share one summary builder, so both report the same
 numbers. The title states the outcome, the body gives the scanned total, the
 actionable counters, then the tracker split.
 
-`format = "plain"` (default) produces aligned text:
+`format = "plain"` (default) produces a compact, grouped summary:
 
 ```
 qbit-maid: 7 torrents removed
 
 Scanned 42 torrents in 12s
 
-Removed          7
-Orphaned         4
-Ignored          5
-Premature        3
+Removed 7  ·  Orphaned 4
+Ignored 5  ·  Premature 3
 
-Protected       10
-Non-protected   20
+Protected 10  ·  Non-protected 20
 ```
 
-`format = "html"` bolds the labels and counts using Pushover's HTML subset
-(`html=1` is set automatically). Apprise has no HTML support, so it always
-receives the plain body.
+Counters are grouped two per line and joined with a middle dot rather than
+padded into columns. Pushover renders the body in a proportional font, so
+space-padded columns collapse into a ragged list on a phone — the separator
+survives any font.
 
-Setting `use_emoji = true` switches both styles to `emoji label: value` rows:
+`format = "html"` bolds the labels using Pushover's HTML subset (`html=1` is
+set automatically). Apprise has no HTML support, so it always receives the
+plain body.
+
+Setting `use_emoji = true` prefixes each counter with an emoji marker:
 
 ```
-🗑️ Removed: 7
-👻 Orphaned: 4
-⏭️ Ignored: 5
-🐣 Premature: 3
+🗑️ Removed 7  ·  👻 Orphaned 4
+⏭️ Ignored 5  ·  🐣 Premature 3
+
+🛡️ Protected 10  ·  🌐 Non-protected 20
 ```
 
+To preview the result without sending a push, render the real
+`build_summary()` output as a phone-width mockup:
+
+```
+python3 docs/notify-preview.py /tmp/notify.png
+```
+
+Pass `--mock` to render the design sketches instead of the live output.
+
 Other options:
 
 - `include_hostname` — add a `Host:` line, useful when several instances notify