docs(claude): drop the deleted dev up CLI from seeded orientation files

The matured dev-env backport removed dev.sh (which provided
`dev up/down/logs/shell`) but the seeded CLAUDE.md files still told
users — and Claude sessions, since these symlink into ~/dev/ — to run
those commands. `dev` is now just a nav function (cd $DEV_ROOT), so
`dev up` silently cd'd and started nothing.

Rewrite both Quick-commands / Default-dev-workflow sections to the real
command set (lb/prb/dev-status/regtest-start/dev-deploy) and document
that FakeWallet startup is manual — there is no `dev up` wrapper.

files/lnbits-CLAUDE.md

@@ -70,9 +70,19 @@ Full reference: `docs/lnbits-upstream-flow.md`.
 
 ## Default dev workflow
 
+There is no `dev up` wrapper. Start lnbits directly from a worktree:
+
 ```
-dev up                  # FakeWallet, instant
-dev up --regtest        # multi-node regtest (slower boot, real channels)
+lb dev                  # cd ~/dev/lnbits/dev
+LNBITS_BACKEND_WALLET_CLASS=FakeWallet <lnbits run command>   # instant, no docker
+```
+
+For real channels/payments, use the regtest stack (gated on
+`devEnv.regtest.enable`; needs docker):
+
+```
+regtest-start dev       # build lnbits from ~/dev/lnbits/dev, bring the stack up
+regtest-stop
 ```
 
 Use **FakeWallet** for extension CRUD / UI / API work. Spin up