feat: provision Alpine LXC 136 running Atheos, wired to Gitea

Provisions a LAN-only browser code editor (Atheos) in an Alpine 3.23 LXC on the
scotty PVE node, with armistace/blog cloned and ready to edit. Built via the
AI-DLC workflow; the full process trail is in aidlc-docs/.

Deliverables
- scripts/provision.sh          rebuild the guest from scratch (re-runnable)
- scripts/update-atheos.sh      move Atheos to latest upstream and RE-PIN
- scripts/build-and-test.sh     captures evidence for every acceptance criterion
- files/atheos.conf             nginx vhost (socket path byte-matches the FPM pool)
- files/ssh-config              ~atheos/.ssh/config deploy-key alias
- RUNBOOK.md                    operational guide (START AT STEP 1)
- docs/security-notes.md        credential model + wider-web hardening TODOs
- docs/resiliency-notes.md      what a non-PoC deployment would need

Design decisions
- D1 no git identity is configured by the agent; the operator sets it. Git will
  refuse the first commit until then, which is deliberate (requirement FR-11).
- D2 Atheos pinned to commit f90cd18 (build 611) with a verified tarball sha256,
  plus update-atheos.sh as the deliberate escape hatch.
- D3 nginx :80, web root /var/www/atheos, php-fpm over a unix socket.
- D6 git auth is a per-repository DEPLOY KEY scoped to armistace/blog, not a
  personal access token (a PAT's write:repository scope reaches every repo the
  account can write).

Verified on the live guest (40 checks, 0 failures)
- AC-2  Atheos served over HTTP 200 by nginx+php-fpm; socket paths byte-match
- AC-3  20 posts + themes/cleanblog present; owned by the php-fpm user
- AC-4  all five writable paths writable as the service user
- AC-5  remote targets armistace/blog; deploy key authenticates over SSH
- AC-6  survival proven with a real container restart, marker byte-identical
- AC-8  no python/pelican/pip/make and no DB engine - scope boundary enforced
- FR-11 git identity is empty; deploy key mode 600 owned by the service user

Traps documented in the RUNBOOK (each cost real debugging time)
- The Gitea SSH user is `gitea`, NOT `git` (app.ini SSH_USER=gitea). With `git`,
  sshd answers "Invalid user git" and rejects before reading authorized_keys,
  which is indistinguishable from a bad key.
- The Gitea SSH endpoint is the LAN address (:22 is not forwarded publicly).
- `uptime` and `free` report the PVE HOST inside an LXC without lxcfs, so a
  container that just restarted can claim days of uptime.

aidlc-docs/aidlc-state.md

@@ -0,0 +1,64 @@
+# AI-DLC State Tracking
+
+## Project Information
+- **Project**: atheos-blog-lxc
+- **Start Date**: 2026-09-29T05:05:05Z
+- **Current Stage**: INCEPTION — Workspace Detection (complete) → Requirements Analysis
+- **Deploy Target**: Proxmox LXC (Alpine 3.23) — NOT the K3s cluster. Deploy-target flavour:
+  "self-hosted LXC", so `k3s-flavor.md` does NOT apply and no CI/registry pipeline is wired.
+
+## Workspace State
+- **Existing Code**: No (greenfield repo; the blog being edited is a separate existing repo)
+- **Programming Languages**: none yet (deliverable is provisioning/docs; target app is PHP)
+- **Build System**: none (Alpine + nginx/php-fpm provisioning; Makefile-driven install script)
+- **Reverse Engineering Needed**: N/A for the repo; brownfield recon done on the *estate*
+  (blog repo, Gitea, PVE templates) — see audit.md Workspace Detection entry.
+- **Workspace Root**: /home/hermes/dev/atheos-blog-lxc
+
+## Existing Estate Facts (load-bearing — verify before trusting)
+- **Atheos** (Atheos/Atheos, 677★, MIT, active): PHP web IDE, **no database**. Install = drop
+  files in a web root + make `config.php`, `data/`, `workspace/`, `plugins/`, `themes/` writable.
+  Optional PHP extensions for the plugin marketplace: **ZIP, OPENSSL, MBSTRING**, and
+  `allow_url_fopen=On`. Has git integration via its **codegit** component.
+- **blog repo** = `armistace/blog` (public, default branch `master`). It is a **Pelican static
+  site**, not plain content:
+  - `src/content/*.md` (~20 posts) + `src/content/images/`
+  - `src/themes/cleanblog/`
+  - `src/pelicanconf.py`, `src/devpelconf.py`, `src/publishconf.py`, `src/Makefile`, `src/tasks.py`
+  - `requirements.txt`: `pelican[markdown]`, `markdown-markup-emoji`
+  - Root: `Dockerfile` (python:slim → `make html` → `make serve-global`), `kube/`, `.gitea/workflows/build_push.yml`
+  - **Implication**: to *regenerate/publish* the site you need Python+pelican (`make html`, `make github`).
+    Atheos alone edits the markdown + git and cannot build it.
+- **PVE**: template `alpine-3.23-default_20260116_amd64.tar.xz` available (must download first).
+  Node `janeway` (.225) = 15.9 GB RAM (3.3 GB free), storage `extra` 874 GB free.
+  Node `data` (.42) = 7.9 GB RAM (only ~0.95 GB free) — avoid heavy guests.
+- **Gitea**: LXC 109 on data (.42), guest .155, **1.27.3** (post-CVE-2026-60004 remediation).
+  `.151` = LXC 110 **nginxpm (NPM)** which fronts it; runners are on k3s nodes .161/.162.
+- **Access**: `root@<pve-node>` + `pct exec`. Gitea token in `~/.hermes/credentials/gitea-api.env`.
+
+## Code Location Rules
+- **Application Code**: Workspace root (NEVER in aidlc-docs/)
+- **Documentation**: aidlc-docs/ only
+- **Structure patterns**: See code-generation.md Critical Rules
+
+## Extension Configuration
+| Extension | Enabled | Decided At |
+|---|---|---|
+| security-baseline | ❌ No (opt-out; TODOs documented in docs/security-notes.md) | Requirements Analysis |
+| resiliency-baseline | ❌ No (opt-out; TODOs documented in docs/resiliency-notes.md) | Requirements Analysis |
+| property-based-testing | ❌ No | Requirements Analysis |
+
+## Stage Progress
+### 🔵 INCEPTION PHASE
+- [x] Workspace Detection
+- [ ] Reverse Engineering (brownfield only — N/A; estate recon done inline)
+- [x] Requirements Analysis
+- [x] User Stories (SKIPPED — user-confirmed; substituted with a requirement→unit map)
+- [x] Workflow Planning
+- [x] Application Design (minimal depth — 5 design artifacts; D6 deploy-key model)
+- [x] Units Generation (5 units; requirement→unit map substitutes the story map)
+### 🟢 CONSTRUCTION PHASE
+- [ ] Per-Unit Loop
+- [ ] Build and Test
+### 🟡 OPERATIONS PHASE
+- [ ] Operations (placeholder)