.ssp: omit empty-value array property entries

Add empty-string guards to array property loops
(.stow_link, .lev4_subtoc, .anchor_tag) so entries with
zero-length values are not emitted. Empty properties have
no value for PEG parsing - absent lines are faster to skip
than matching a property name to find an empty value.

Removes 1488 empty .anchor_tag: lines from Wealth of
Networks .ssp alone.

Co-Authored-By: Anthropic Claude Opus 4.6 (1M context)

1 files changed, 6 insertions, 3 deletions

diff --git a/org/out_src_abstraction_peg_text.org b/org/out_src_abstraction_peg_text.org
index 1b6517b..2f2c798 100644
--- a/org/out_src_abstraction_peg_text.org
+++ b/org/out_src_abstraction_peg_text.org
@@ -341,7 +341,8 @@ template spineAbstractionTxt() {
         /+ ↓ stow (extracted links) +/
         if (obj.stow.link.length > 0) {
           foreach (lnk; obj.stow.link) {
-            output ~= ".stow_link: " ~ lnk;
+            if (lnk.length > 0)
+              output ~= ".stow_link: " ~ lnk;
           }
         }
 
@@ -372,13 +373,15 @@ template spineAbstractionTxt() {
         /+ ↓ lev4 subtoc +/
         if (obj.tags.lev4_subtoc.length > 0) {
           foreach (st; obj.tags.lev4_subtoc) {
-            output ~= ".lev4_subtoc: " ~ st;
+            if (st.length > 0)
+              output ~= ".lev4_subtoc: " ~ st;
           }
         }
         /+ ↓ anchor tags +/
         if (obj.tags.anchor_tags.length > 0) {
           foreach (at; obj.tags.anchor_tags) {
-            output ~= ".anchor_tag: " ~ at;
+            if (at.length > 0)
+              output ~= ".anchor_tag: " ~ at;
           }
         }