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>

.agents/skills/rewriting-technical-prose-naturally/SKILL.md

@@ -22,12 +22,34 @@ keep the meaning — but fix the sentence by *adding a short clause that states
 twisting a word into a shape no one uses. A sentence that is technically exact and unspeakable is a
 sentence that still needs work.
 
-Before the first rewrite in a task, read both references:
+Before the first rewrite in a task, read all three references:
 
 - [references/document-skeleton.md](references/document-skeleton.md) — how a Korean tech blog article
   is ordered: opener, audience bar, definition section, case template, closing.
+- [references/article-shape.md](references/article-shape.md) — **how much explanation goes inside a
+  section.** Ordering can be right while the piece still reads thin. This is the one that fails most often.
 - [references/korean-tech-blog-register.md](references/korean-tech-blog-register.md) — what Korean
   tech blogs actually do with definitions, verbs, particles, subjects, headings, and numbers.
+
+## Unpacking is not inventing
+
+A compressed source and a thin source look the same on the page, and they are not. Four moves recover
+what the source already holds. None of them adds a fact.
+
+| Move | Where the material comes from |
+|---|---|
+| **Restore a number the prose rounded off** | The record's own fields — `검증 환경`, `재현 조건`, the evidence file, the `확인한 것` table. A body that says 「세 곳에서 막는다」 while `검증 환경` lists ports 8088 · 8081 · 4180 dropped those numbers on the way in. Put them back. |
+| **Define a term at its first use** | The standard, public definition of a term the source already uses. `MessageDigest.isEqual`, `auth_request`, `forward-auth` — one clause each, where the reader first needs it. |
+| **Turn a table row into a sentence** | The table already in the source. A row like `host port 닫힘 \| 외부 직접 경로` becomes the sentence that says which ports, closed how, and what still gets through. The table stays as the summary. |
+| **Show the code the source only named** | The repository, at the revision the record pins. `EdgeIdentityController.currentUser` named in prose becomes the method body — trimmed to what the section is about, cut marked `// …`. |
+
+What is still off limits: a measurement nobody took, a cause the source did not establish, a benefit or
+drawback the source did not claim, a failure story that did not happen. If a section needs a number that
+was never measured, write that it was not measured and leave the slot open — `article-shape.md` shows the
+six articles doing exactly that.
+
+**The test:** point at the sentence you added and name the field, file, or line it came from. If you
+cannot, it is invention, not unpacking.
 - [references/regression-examples.md](references/regression-examples.md) — rewrites that failed and why.
 
 Read the complete source and the nearby context needed to interpret pronouns, comparisons, and causes.
@@ -57,6 +79,11 @@ named here so the spine stays visible.
 
 - Do not shorten merely to look more human.
 - **Do not remove implementation detail because the paragraph feels dense.** Density is not a style defect.
+- **A section is a claim plus its evidence.** Evidence is code, output, a number, or a table — at least
+  one. A section that is two paragraphs of prose with neither was cut at the wrong place; merge it with
+  its neighbour. `references/article-shape.md`.
+- **Do not let a table carry an explanation that was never written.** Tables summarise prose that already
+  ran. If the table is the first place a distinction appears, write the prose first and keep the table.
 - Do not create `처음에는`, `해보니`, `놀랍게도`, `저희는` or other experience language unless the source
   records that experience.
 - **Do not imitate one company's or one author's voice.** `style_profile.mjs` measures against five
@@ -459,6 +486,20 @@ where the source really contrasts, `관계` is right inside `연관 관계`, and
 rule, re-run it against them — a rule those articles fail is a rule that is stricter than the standard,
 and it will push you into contorting prose to satisfy a check no human writer meets.
 
+Then measure depth. `check_prose.mjs` reads sentences; this reads how much is in them.
+
+```bash
+node .agents/skills/rewriting-technical-prose-naturally/scripts/density.mjs [--구조] <파일.md>
+```
+
+Default thresholds are for a piece that reports something measured — a Case. Pass `--구조` for one that
+explains how something works — a Concept — where two to five figures is normal and thirteen is not.
+Ranges come from the six articles in [examples/](examples/).
+
+**These are not targets to hit.** A low count names a place where explanation is missing; adding
+paragraphs to move the number produces a worse document that passes. Read the flagged line, find the
+section it points at, and decide whether the source actually holds what belongs there.
+
 Then take the style profile:
 
 ```bash
@@ -477,6 +518,8 @@ every rule above still applies, and the read-aloud test below is the one that de
 
 ## 참조
 
+- `examples/` — **통과 기준이 되는 글 여섯 편.** 이 정도로 읽히면 통과다
+- `references/article-shape.md` — 한 절 안을 무엇으로 채우는가. 잰 값과 그 값을 만드는 것
 - `references/regression-examples.md` — 고친 예와 실패 이유
 - `references/protected-content.md` — 옮길 때 한 글자도 바꾸면 안 되는 것
 - `references/editorial-rules.md` — 편집 규칙