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/prds/0018-compose-per-instance.md

@@ -290,7 +290,7 @@ After this PRD:
 
 ### Cleanup CLI
 
-`./cli.py cleanup` switches from "list every container with prefix
+`bot-bottle cleanup` switches from "list every container with prefix
 `bot-bottle-` and every network with prefix `bot-bottle-net-`
 or `bot-bottle-egress-`" to:
 
@@ -369,7 +369,7 @@ Sized for one PR each, in order.
    `docker compose up -d` + attach + teardown. Per-sidecar `start()`/
    `stop()` lifecycle methods deleted in the same chunk. Compose-
    log dump on teardown added.
-4. **Cleanup CLI on compose.** Switch `./cli.py cleanup` to
+4. **Cleanup CLI on compose.** Switch `bot-bottle cleanup` to
    `docker compose ls`-based discovery; keep prefix-scan as
    fallback for one release.
 5. **Dashboard.** Decide on the discovery question (open question