feat(claude): seed curated CLAUDE.md files into ~/dev/ workspace

Adds the omnixy-pattern out-of-store-symlink wiring so consumers can
opt into Claude Code orientation without copying anything by hand.
Files live in lnbits-sensei (so they evolve via PR), symlinks point
back at the consumer's checkout (so edits take effect on the next
Claude session without a nixos-rebuild).

New files under files/:

- dev-CLAUDE.md — generic workspace orientation. Workspace layout,
  quick command set, pointers to docs/. Opt-in (clobbers an existing
  ~/dev/CLAUDE.md, so off by default).
- lnbits-CLAUDE.md — per-project orientation for the lnbits worktree
  subtree. Inline summary of the four most-stepped-on gotchas
  (settings precedence, Quasar UMD self-closing rule, auth-decorator
  distinctions, upstream PR target = `dev` not `main`) plus pointers
  to the docs/ for full reference.

New options under lnbits-sensei.devEnv:

- scaffoldPath — absolute path to the consumer's lnbits-sensei
  checkout. types.str (not types.path) intentionally: types.path
  would copy the file into the Nix store and defeat
  mkOutOfStoreSymlink. Required when any claude.* flag is on.
- claude.enable — seeds ~/dev/lnbits/CLAUDE.md.
- claude.workspaceOrientation — additionally seeds ~/dev/CLAUDE.md.

Wiring lives in home.nix (gated via `osConfig.lnbits-sensei.devEnv.*`)
rather than the dev-env NixOS module, since the file destinations are
under home-manager's purview and the home-manager scope is where
`mkOutOfStoreSymlink` is in scope.

`nix flake check` stays green — `optionalAttrs` is lazy, so
`scaffoldPath` isn't accessed when claude.{enable,workspaceOrientation}
are both false (their defaults).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

files/dev-CLAUDE.md

@@ -0,0 +1,61 @@
+# `~/dev` — lnbits dev workspace
+
+You're working in a dev workspace bootstrapped by **lnbits-sensei**.
+This file is workspace-level orientation; per-project CLAUDE.md files
+(e.g. `~/dev/lnbits/CLAUDE.md`) layer project-specific gotchas on top.
+
+> This file is a symlink into your lnbits-sensei checkout's
+> `files/dev-CLAUDE.md` (via home-manager's `mkOutOfStoreSymlink`).
+> Edits should happen in the checkout and be committed there.
+
+## Layout
+
+```
+~/dev/
+├── repos/                      # bare git repos, one per project
+├── <project>/<worktree>/       # worktrees per branch
+├── upstream-prs/<topic>/       # PR branches against upstreams
+├── shared/, scratch/           # workspace utilities
+└── refs/                       # curated reference repos (optional)
+```
+
+Rationale: bare-repos + per-project-worktree directories means one git
+object database per project (no clone-per-branch churn) and an explicit
+PR contract in `upstream-prs/`. See the lnbits-sensei README's
+"Workspace layout" section for the full reasoning.
+
+## Quick commands
+
+- `dev up [--fakewallet|--regtest]` — start the lnbits dev server.
+  Default `--fakewallet` is instant, no docker, good for
+  extension/UI/API work.
+- `dev down` / `dev logs` / `dev shell` — control / inspect.
+- *(planned)* `prb <repo> <branch>` — create a PR worktree branched
+  from `upstream/main` under `~/dev/upstream-prs/`.
+- *(planned)* `lb <worktree>` — cd shortcut into `~/dev/lnbits/<worktree>`.
+
+## Reference docs
+
+Full reference lives in the lnbits-sensei checkout's `docs/`:
+
+- `docs/remotes.md` — three remote-topology patterns (upstream-only /
+  github-fork / multi-remote-with-private).
+- `docs/upstream-prs.md` — PR workflow with a primer for anyone new
+  to fork-based contribution.
+- `docs/lnbits-upstream-flow.md` — how `lnbits/lnbits` itself moves
+  (the `dev` / `main` branch split, squash-merge convention).
+- `docs/lnbits-workspace-notes.md` — practical gotchas: port choice,
+  `LNBITS_SRC` build-context traps, extension-folder-upgrade wiping
+  forks, Nostr key handling, CLINK scope, fork versioning, **settings
+  precedence (`.env` vs DB)**.
+
+## Per-project orientations
+
+Per-project CLAUDE.md files are placed at the worktree root:
+
+- `~/dev/lnbits/CLAUDE.md` — LNbits dev gotchas (settings precedence,
+  frontend rules, auth decorators, …).
+
+These are also symlinked from your lnbits-sensei checkout (under
+`files/`); the seeding is driven by `lnbits-sensei.devEnv.claude.*`
+options.

files/lnbits-CLAUDE.md

@@ -0,0 +1,94 @@
+# `~/dev/lnbits` — LNbits dev orientation
+
+Per-project CLAUDE.md for the LNbits worktree subtree. Workspace-level
+orientation is at `~/dev/CLAUDE.md` (when wired). Full reference
+material lives in your lnbits-sensei checkout under `docs/`.
+
+> This file is a symlink to `files/lnbits-CLAUDE.md` in your
+> lnbits-sensei checkout. Edits should happen there.
+
+## Critical gotchas (read first)
+
+### Settings: `.env` seeds the DB on first boot, then DB wins
+
+After first boot, **editing `.env` and restarting changes nothing**
+for editable fields. Only `ReadOnlySettings` (`host`, `port`,
+`lnbits_path`, `lnbits_data_folder`, `lnbits_extensions_path`,
+`lnbits_database_url`, `auth_secret_key`, `first_install_token`,
+`lnbits_title`, `lnbits_admin_ui`, `lnbits_allowed_funding_sources`)
+re-read env every boot.
+
+Editable settings (site title, fees, watchdog, funding-source
+credentials, the whole Admin UI form) change only via:
+
+- `PUT /api/v1/settings` (Admin UI), or
+- Clearing the relevant rows in the `system_settings` table.
+
+Deploy-side: declarative env vars are a *seed* for editable fields,
+not authoritative. Plan accordingly.
+
+Full reference: `docs/lnbits-workspace-notes.md` → "Settings precedence".
+
+### Frontend templates: NO self-closing tags
+
+LNbits pages load Vue 3 + Quasar 2 as UMD globals. The browser's
+HTML parser doesn't honor self-close on non-void elements — the
+close tag gets implied at the wrong place and subsequent siblings
+end up inside the prior component.
+
+```html
+<q-input v-model="foo" label="Foo"></q-input>   <!-- ✓ correct -->
+<q-input v-model="foo" label="Foo" />            <!-- ✗ silently broken -->
+```
+
+Applies to `lnbits/templates/*.html`, every extension's `templates/`,
+every fork. Fine in `.vue` SFCs (the build step rewrites them) — if
+you copy a snippet from a Vue SFC repo into an LNbits template,
+**expand all self-closing tags before saving**.
+
+### Auth decorators
+
+Easy to confuse. Different scopes:
+
+| Decorator | Auth scope |
+|---|---|
+| `require_invoice_key` | Wallet invoice key — read access |
+| `require_admin_key` | Wallet admin key — write to **own wallet only** |
+| `check_admin` | **LNbits instance admin** (super_user / admin users) |
+| `check_super_user` | LNbits super user only |
+
+`require_admin_key` ≠ `check_admin`. Use `check_admin` for
+cross-user / admin-only endpoints.
+
+### Upstream PRs target `dev`, not `main`
+
+PRs to `github.com/lnbits/lnbits` go to `dev`. `main` only moves on
+release merges. Use lowercase conventional-commit titles
+(`feat:`, `fix:`, `chore:`, `chore(deps):`, `docs:`, `ci:`).
+
+Full reference: `docs/lnbits-upstream-flow.md`.
+
+## Default dev workflow
+
+```
+dev up                  # FakeWallet, instant
+dev up --regtest        # multi-node regtest (slower boot, real channels)
+```
+
+Use **FakeWallet** for extension CRUD / UI / API work. Spin up
+**regtest** only when actual channel/payment behavior is under test.
+
+## Key paths
+
+- `~/dev/lnbits/main/` — worktree on `main` (your fork's day-to-day)
+- `~/dev/lnbits/dev/` — worktree on `dev` (integration / staging)
+- `~/dev/upstream-prs/lnbits-<topic>/` — PR worktrees branched from
+  `upstream/main`
+- `~/dev/repos/lnbits.git` — the bare repo all the above point at
+
+## When in doubt
+
+The canonical reference for any of the above lives in your
+lnbits-sensei checkout's `docs/`. Trust the docs over this file when
+they diverge — this CLAUDE.md is a quick-reference; the docs are the
+source of truth.