sqlite db abstraction: make readable as read-only

drop WAL so the file can be read read-only: journal_mode=WAL was
set in the file header and A WAL database cannot be opened by a
reader that cannot also write beside it (this ruled out a
read-only directory, read-only media, and anything that wants to
read the artefact where it sits).

(assisted by Claude-Code)

2 files changed, 10 insertions, 12 deletions

diff --git a/src/sisudoc/ocda/abstraction/ssp.d b/src/sisudoc/ocda/abstraction/ssp.d
index fc7dbd3..5e9347f 100644
--- a/src/sisudoc/ocda/abstraction/ssp.d
+++ b/src/sisudoc/ocda/abstraction/ssp.d
@@ -315,9 +315,6 @@ template spineAbstractionTxt() {
         if (obj.metainfo.object_number_off) {
           output ~= ".ocn_off: true";
         }
-        // if (obj.metainfo.o_n_type != 0) {
-        //   output ~= ".o_n_type: " ~ obj.metainfo.o_n_type.to!string;
-        // }
         if (obj.metainfo.is_of_type.length > 0) {
           output ~= ".is_of_type: " ~ obj.metainfo.is_of_type;
         }
@@ -402,16 +399,10 @@ template spineAbstractionTxt() {
           }
           if (obj.table.heading) {
             output ~= ".table_header: true";
-         }
-          // if (obj.table.walls) {
-          //   output ~= ".table_walls: true";
-          // }
+          }
         }
         /+ ↓ code block properties +/
         if (obj.metainfo.is_a == "code") {
-          // if (obj.code_block.syntax.length > 0) {
-          //   output ~= ".code_syntax: " ~ obj.code_block.syntax;
-          // }
           if (obj.code_block.linenumbers) {
             output ~= ".code_linenumbers: true";
           }
diff --git a/src/sisudoc/outputs/io_out/create_abstraction_db.d b/src/sisudoc/outputs/io_out/create_abstraction_db.d
index ba83736..d1f3f53 100644
--- a/src/sisudoc/outputs/io_out/create_abstraction_db.d
+++ b/src/sisudoc/outputs/io_out/create_abstraction_db.d
@@ -91,8 +91,15 @@ template spineAbstractionDb() {
 
     /+ ↓ open database and create schema +/
     auto db = Database(db_file);
-    db.run("PRAGMA journal_mode=WAL");
-    db.run("PRAGMA synchronous=NORMAL");
+    /+ ↓ write once, read many: no WAL.
+         a WAL stamped file cannot be opened by a reader that cannot write
+         beside it (SQLITE_READONLY on a read-only directory, and inside a
+         zip or on read-only media), and this database has one writer and no
+         concurrency, so WAL buys nothing here. MEMORY journal keeps the bulk
+         load fast without leaving that mark on the file.
+    +/
+    db.run("PRAGMA journal_mode=MEMORY");
+    db.run("PRAGMA synchronous=OFF");
 
     db.run("
       CREATE TABLE metadata (