docs(keycloak-session-store): import the session-storage lab as a new project

The keycloak project ended with four open questions that design could not
settle. A two-VM lab was built to answer them by measurement, and this is
that material: 26 experiments, 125 raw command outputs, 22 browser captures.

Follows the import procedure in README.md.

  source/     the originating repository verbatim — 78 documents, 28 SVGs,
              8 manifests, plus .source-revision recording the commit
  final/      the SSOT
    document.md   729 lines written from the 29 experiment documents, not
                  concatenated: what was predicted, what was measured, and
                  where the measurement itself was wrong
    evidence/raw    125 outputs, flattened to <experiment>__<file> because
                    the originals collided (01-baseline.txt appeared three
                    times) and the audit only globs the top level
    evidence/meta   one per raw file; command and exitCode are null and the
                    README says why rather than inventing them
    evidence/browser  22 captures
    assets/       three diagrams through techviz
    .techviz/     their VizSpecs

A separate project rather than an addition to keycloak: the B-layer answers
that project's four questions, but the A, C and D layers are about cluster
failure, SSO and operations, and one document.md should hold one subject.
The four question records there can point here through 관계.

Recorded rather than papered over: only three of the 28 diagrams were
remade. The repository forbids hand-drawn SVG and forbids titles inside the
canvas; all 28 originals carry both, so converting them is redrawing, not
reformatting. They stay in source/ and the gap is written into the document.

verify-pipeline.py passes. audit-records.py reports no issues.

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

docs/clean-architecture-backend-template/final/evidence/raw/065a-pg-range-escaped-quote-probe.java

@@ -0,0 +1,25 @@
+package dev.caskeleton.adapter.outbound.persistence.postgresql.range;
+public final class RangeProbe {
+  public static void main(String[] args) {
+    var codec = new PgRangeCodec<String>(s -> s, s -> s);
+    var cases = new String[][] {
+      {"comma", "left,inside", "right"},
+      {"quote", "left\"inside", "right"},
+      {"quote-comma", "left\",inside", "right"},
+      {"backslash-quote-comma", "left\\\",inside", "right"}
+    };
+    for (var c : cases) {
+      var range = PgRange.closedOpen(c[1], c[2]);
+      String literal = codec.format(range);
+      try {
+        var parsed = codec.parse(literal);
+        System.out.println(c[0] + ".literal=" + literal);
+        System.out.println(c[0] + ".roundTrip=" + parsed.equals(range));
+        System.out.println(c[0] + ".lower=" + parsed.lower().orElse("<none>"));
+      } catch (Throwable t) {
+        System.out.println(c[0] + ".literal=" + literal);
+        System.out.println(c[0] + ".error=" + t.getClass().getSimpleName() + ":" + t.getMessage());
+      }
+    }
+  }
+}