docs: rewrite documentation for new users — verify every claim against the code

The docs had drifted from reality in ways that actively mislead new users:

- README: bare :latest/:cli image tags don't exist (manifest unknown);
  lpb default mode is the Pi CLI (not VSCodium welcome screen); wrong
  mount paths (/workspace/... vs /home/lpb/workspace/...); 'pi login'
  CLI subcommand does not exist (/login is a TUI command); 'update'
  binary does not exist (pi update --extensions); stale pi upstream
  baseline (v0.83.0 → v0.84.2); dead lpb-stack/lpb-stack* repo links;
  CI triggers described as main-only (dev + main)
- lpb-cli.md: install claimed sudo + /usr/local/bin (it's ~/.local/bin,
  no sudo); LPB_MODE/LPB_TAG env vars do not exist in the code; config
  file names wrong; fake 'lpb run'/'lpb exec' subcommands; self-update
  described as automatic (it is lpb --update, branch follows the tag);
  added the real flags (--web/--shell/--ssh, --dev/--main, aliases,
  pi passthrough) and the real image-resolution rules
- env-vars.md: same non-existent vars; .env location fixed (project
  workspace, optional); real lpb.conf.env defaults; VISION_MODEL does
  not exist
- lpb-config.md: promote description used origin/main+origin/dev for
  all repos (forks use lpb/lpb-dev); added the 'local stable ahead'
  case
- config-repo.md: pin format was invented (real: packages array with
  git:owner/repo@tag strings); directory tree corrected against the
  actual config repo; skills list corrected (3 shipped skills, not 1)
- lpb-memory-overview.md: config table did not match the template or
  extension defaults; llmModelOverride default is the MAIN session
  model (not qwen3.5-9b-FLM); template ships legacy-inject
- lpb-memory-analysis.md: marked as a point-in-time diagnostic
- CONTRIBUTING.md: removed dead repo links; feature branches off the
  default branch (dev/lpb-dev), not the stable branch
- new doc/forking.md: extracted the Forking & Repointing guide from the
  README (README is the docs-site home; kept it lean for new users)
- .env.example: stale ~/.localpibox/ paths → ~/.lpb-stack/
- entrypoint comments: bare :cli/:web usage examples → :latest-cli/web
- .gitignore: ignore the derived docs/ + site/ build trees

Author: localpibox

.env.example

@@ -44,8 +44,8 @@ LPB_AGENT_BROWSER_SESSION=${PI_WORKTREE_ID}
 
 # Agent-browser persistent storage on host
 # Chrome download, browser profiles, and session state survive container rebuilds.
-# Default: ~/.localpibox/agent-browser/
-# LPB_AGENT_BROWSER_DIR=$HOME/.localpibox/agent-browser
+# Default: ~/.lpb-stack/agent-browser/
+# LPB_AGENT_BROWSER_DIR=$HOME/.lpb-stack/agent-browser
 
 # Chrome launch args (container-safe defaults)
 LPB_AGENT_BROWSER_ARGS="--no-sandbox,--no-first-run,--disable-gpu,--disable-crashpad"
@@ -82,5 +82,5 @@ LPB_AGENT_BROWSER_IDLE_TIMEOUT_MS=300000
 # ─── Persistence ─────────────────────────────────────────────────────────────
 
 # Persist gh CLI auth to ~/.config/gh inside container, stored in
-# ~/.localpibox/state/gh-config on the host (in the state volume).
+# ~/.lpb-stack/state/gh-config on the host (in the state volume).
 # LPB_PERSIST_GH_CONFIG=true

.gitignore

@@ -7,3 +7,8 @@ __pycache__/
 *.pyo
 .env
 node_modules/
+
+# ── Docs site (derived trees — built by scripts/generate.py on the docs
+#    branch; the tracked content lives in doc/, README.md, ...) ───────────
+/docs/
+/site/

CONTRIBUTING.md

@@ -22,13 +22,11 @@ has its own scope:
 | [lemonade-pi-plugin](https://github.com/lpb-stack/lemonade-pi-plugin) | Qwen thinking + vision support (fork) |
 | [pi-subagents](https://github.com/lpb-stack/pi-subagents) | Centralized subagent model registry (fork) |
 | [lpb-memory](https://github.com/lpb-stack/lpb-memory) | Persistent memory / session search extension |
-| [lpb-stack](https://github.com/lpb-stack/lpb-stack) | Project overview & stack reference |
-| [lpb-stack.github.io](https://github.com/lpb-stack/lpb-stack.github.io) | GitHub Pages project site |
 
 ### Process
 
-1. Fork the repo and create a feature branch off its stable branch
-   (`main` for own repos, `lpb` for forks).
+1. Fork the repo and create a feature branch off its default branch
+   (`dev` for own repos, `lpb-dev` for forks).
 2. Make focused changes. **Prefer minimal, targeted patches** over broad
    rewrites.
 3. For forks, keep work as a **single squashed commit** on `lpb` so the delta