feat: draw the grid by default, --markdown to opt out

A markdown table carries no borders of its own; whether any get drawn is
up to the renderer, and terminal renderers mostly draw none. Emitting the
grid directly makes the output look the same everywhere it lands.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

skills/hourlog/SKILL.md

@@ -43,9 +43,13 @@ missing step if not.
 python3 <skill-dir>/scripts/scan-activity.py --week last
 ```
 
-Prints a markdown table: one row per day, one column per project holding
+Prints a drawn grid: one row per day, one column per project holding
 `hours · share · active minutes`, then a totals row. That table is the
-deliverable — paste it as-is rather than restating it in prose.
+deliverable — show it as-is, inside a fenced code block so the terminal
+renderer leaves the borders alone, rather than restating it in prose.
+
+`--markdown` swaps the grid for pipes when the destination renders tables
+itself (a PR body, an issue, a doc).
 
 The unit behind it is a 5-minute slot in which at least one message was
 written, deduplicated per project — so a 40-subagent swarm on one project