Make the docs state things rather than argue them

The site read as a design journal: rationale paragraphs, hedges
("deliberately", "on purpose", "genuinely"), meta-commentary about the docs
themselves, and one em-dash every ten lines carrying an aside.

Roughly twenty rationale blocks are gone or reduced to what a reader needs
in order to use the thing. Em-dashes go from 507 to 135, and what is left is
structural rather than prose: list and definition separators, table cells,
and four inside code blocks that quote what the CLI actually prints.

Also: api.example.com becomes api.fluksio.com (the emails stay, since
bootstrap.py really defaults to admin@example.com and RFC 2606 reserves it);
the mqtt table gains the two settings it had drifted behind on and inject's
wording matches the engine; llms.txt lists the two connector pages that were
in the nav but not in it; and the two device/device_policy notes now agree.

Builds clean under `zensical build --strict`.

docs/getting-started/index.md

@@ -1,8 +1,6 @@
 # Pick your starting point
 
-People arrive at Fluksio from two directions, and the honest answer to "how do
-I set this up?" is different for each — not just in the commands, but in how
-much of an afternoon it is reasonable to spend.
+Setup differs depending on what you are here for. Pick the path that matches.
 
 Pick the one that sounds like you. Everything past this section is the same for
 both.
@@ -52,8 +50,8 @@ Some rough tells:
 | **Data lives in** | SQLite beside the flows | InfluxDB, usually |
 | **The thing you look at** | run history and loss curves | a dashboard, maybe on a wall |
 
-If both describe you — a lab with instruments to drive *and* models to
-fit — start with the data-science path. It is the smaller instance, and it
+If both describe you (a lab with instruments to drive *and* models to fit),
+start with the data-science path. It is the smaller instance, and it
 grows into the other one without being reinstalled: the same engine, the same
 flows, just more of them running all the time.