Replace SESSION_LOG.md with correct Dec 20-21 chronology (devcontainer provisioning work only)

SESSION_LOG.md

@@ -5,47 +5,15 @@ Do not rewrite or reorder past entries.
 
 ---
 
-## 2025-12-14
-- Goal: Stabilize zlh-agent provisioning pipeline for game + dev containers + addons without regressing game provisioning.
-- Scope: Agent routing (ctype=dev), local artifacts strategy, addon skeleton, initial end-to-end tests.
-- Adopted single base template approach (zlh-agent template) where agent installs roles at runtime.
-
----
-
 ## 2025-12-20
-- Goal: Restore reliable end-to-end provisioning for **game + dev** without regressions; preserve the explicit orchestration steps/logging.
-
-### Current Architecture Reality (IMPORTANT)
-- We are on **single base template**: `AGENT_TEMPLATE_VMID` is the only template in `.env`.
-- In this workflow, **any zlh-agent code change requires rebuilding + pushing the binary into the template container**.
-  - That effectively means: **agent change = new template promotion**.
-
-### Key Findings / Fixes
-- Game provisioning steps are functioning again and show clear step-by-step orchestration output (allocate VMID → clone → configure → start → IP → agent config → wait → DB save → edge publish).
-- Dev provisioning failure was traced to a **wire contract mismatch** between API JSON and agent `state.Config` struct tags:
-  - Agent expects: `container_type` (snake_case) on the JSON wire
-  - API refactors were sending: `ctype` / `containerType` (camelCase) in some variants
-  - Result: `cfg.ContainerType == ""` on decode → agent routes into game path → errors like:
-    - `unsupported container identity (containerType="" game="")`
-
-### Decision (to minimize churn)
-- Because agent changes force a template promotion in this pipeline, the correct short-term move is:
-  - **Update API to emit `container_type`** to match the existing agent contract
-  - Avoid touching agent code until we intentionally rev the template
-
-### Operational Guardrails
-- Do NOT remove or "simplify" the explicit provisioning steps/logging; they are required for debugging and operator confidence.
-- Treat `container_type` as the canonical wire key until the next planned template rev.
-
----
-
-## 2025-12-21
 - Goal: Restore reliable end-to-end provisioning for devcontainers and agent-managed installs.
 - Observed repeated failures during devcontainer runtime installation (node, python, go, java).
 - Initial assumption was installer regression; investigation showed installers were enforcing contract correctly.
 - Root cause identified: agent was not exporting required runtime environment variables (notably `RUNTIME_VERSION`).
 
-### Devcontainer provisioning investigation
+---
+
+## 2025-12-21
 - Deep dive on zlh-agent devcontainer provisioning flow.
 - Confirmed that all devcontainer installers intentionally require `RUNTIME_VERSION` and fail fast if missing.
 - Clarified that payload JSON is not read by installers; agent must project intent via environment variables.
@@ -66,7 +34,7 @@ Do not rewrite or reorder past entries.
   `/opt/zlh/runtime/<language>/<version>/current`
 
 ### Artifact layout update
-- Artifact naming and layout standardized to simplified form:
+- Artifact naming and layout changed to simplified form:
   - `node-24.tar.xz`
   - `python-3.12.tar.xz`
   - `go-1.22.tar.gz`