docs: name bot-bottle, not ./cli.py, in every instruction

`doctor` told users to run `./cli.py backend setup`. cli.py is a four-line
wrapper at the repo root that calls bot_bottle.cli:main, and it does not ship —
[tool.setuptools.packages.find] includes only bot_bottle*, so anyone who
installed rather than cloned has no such file. Confirmed against a real
install: the user's tree contains exactly one executable, `bot-bottle`, and no
cli.py anywhere, while doctor recommended `./cli.py` three times. Invisible in
development, where ./cli.py works fine from a checkout, which is why only a
clean-install test surfaced it.

The two entry points are the same code, so the fix is to name the one that
always exists. 141 replacements across 45 files: the runtime messages that
caused this, plus README, docs, PRDs, research notes and test prose, so nothing
teaches the invocation a user cannot run.

scripts/demo.sh is deliberately untouched — it *executes* ./cli.py from a
checkout, where that is the correct and available path.

Verified end to end: a sandbox install now reports
"Run: bot-bottle backend setup --backend=firecracker", and bot-bottle is on
that user's PATH. Unit suite unchanged against the pre-existing baseline.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WEfZZhakx13bxTfXcZCoS5

docs/demo.tape

@@ -1,4 +1,4 @@
-# VHS tape — drives `./cli.py start demo` interactively and asks
+# VHS tape — drives `bot-bottle start demo` interactively and asks
 # claude (the AI) to run four probes via natural-language prompts.
 # Setup (manifest + dummy SSH key + image pre-warm) and teardown
 # happen outside the tape; record via `bash scripts/demo-record.sh`,
@@ -29,7 +29,7 @@ Show
 # defaults), one git upstream (unreachable on purpose so gitleaks runs
 # before the gate would forward), and a FAKE_TOKEN env var shaped like
 # a GitHub PAT.
-Type "./cli.py start demo"
+Type "bot-bottle start demo"
 Enter
 Sleep 8s