fix(#3854): write normalization preserves tight multi-line lists (#4049)

* test(#3854): write normalization must preserve tight multi-line lists (failing first)

* fix(#3854): no blank before a bullet whose previous line is an indented continuation

_normalizeMd's 'separate a list from a preceding paragraph' rule inserted
a blank before any bullet whose previous line wasn't a bullet — but an
INDENTED CONTINUATION of the previous multi-line item also isn't a
bullet. Every .md write (phase.complete in the report, but any write
through platformWriteSync) therefore converted tight lists to loose
ones: +61 blank lines on the reporter's 1015-line ROADMAP, one before
each bullet following a wrapped item. Tight and loose lists render
differently, so this was a rendering change plus misleading diff noise;
one-shot (idempotent afterwards), which is why integrity checks on
headings/content passed.

The guard is the mirror image of the after-a-bullet rule two lines
below, which already excludes indented next lines. Paragraph→list and
heading→list separations — the rule's purpose — are pinned unchanged by
the new suite.

* fix(#3854): review fold-ins — ceiling tracks next's 281 + this branch's marker (282), header/require nits

The ceiling is not ratcheted but must track the tree: origin/next raised
it to 281 (sibling branch's marker file); this tree adds one more
(shell-command-projection-md-normalize), so 282/282. Also fixes the test
header's stale pre-rename filename and hoists the inline require to the
file's single import.

* chore(#3854): changeset fragment (pr number backfilled after PR creation)

* chore(#3854): backfill changeset PR number (4049)

---------

Co-authored-by: sim <sim@local>

scripts/lint-allow-test-rule-refs.unverified-ceiling.json

@@ -1,3 +1,3 @@
 {
-  "maxFiles": 281
+  "maxFiles": 282
 }

scripts/lint-test-file-count.allowlist.json

@@ -263,6 +263,14 @@
         "audit-workstream-layouts.test.cjs"
       ],
       "issue": "#3804/#3805 \u2014 audit-layout and acknowledged-marker suites drive the real audit-uat CLI against on-disk fixtures | #3817 \u2014 regression suite proving countReal counts the truncation remainder marker instead of treating it as one phantom item"
+    },
+    "shell-command-projection": {
+      "files": [
+        "shell-command-projection-dispatch.test.cjs",
+        "shell-command-projection-md-normalize.test.cjs",
+        "shell-command-projection-path-sep.test.cjs"
+      ],
+      "issue": "#3854 \u2014 the tight-list suite pins the markdown write-normalizer's blank-line policy through the exported normalizeContent/platformWriteSync seam; a distinct concern from dispatch routing and path separation"
     }
   }
 }