docs: one manual runbook, and ADR statuses that mean something

DEPLOY-WINDOWS-IIS was a second copy of the manual IIS procedure that had
diverged from the first: a different MySQL version (8.0, which reached end of
life in April), a different port, a different plugin list, and a profile file
that does not exist. Two runbooks for one procedure means a reader follows
whichever they found, and one of them was wrong. INSTALL-WINDOWS-IIS covers
everything it did plus a preflight step and the subpath method, so the one
section it uniquely had - redeploying a hand-built server - is folded in there,
with the plugin-chain step it was missing and a note to back up first, and the
duplicate is gone. Everything that pointed at it now points at the survivor.

Three ADR statuses said something untrue.

ADR-013 said PROPOSED while half of it had shipped and ADR-014 had been accepted
on top of it. A decision that has been implemented and depended upon is not
proposed, and leaving one that way devalues every other status in the index. The
catalog half is still unbuilt, which is the ordinary state of an accepted
decision: accepted means settled, not delivered.

ADR-016 said ACCEPTED for a design where nothing is built - the endpoint and
permissions it describes do not exist, so a reader goes looking for them. The
status stands, because the decision does; the header now says so plainly and
points at where today's credentials actually live.

ADR-003 and ADR-004 were ACCEPTED with their own Decision lines still opening
"**PROPOSED:**", which reads as though the decision was never taken.

And the dashboard proposal carried Status: ACCEPTED, which belongs to a decision
record. A proposal is a proposal; the contract it produced is the ADR.

docs/adr/ADR-003-plugin-distribution.md

@@ -25,7 +25,7 @@ Three viable distribution models:
 
 ## Decision
 
-**PROPOSED:** Use a **hybrid model** with two clearly-labeled paths.
+Use a **hybrid model** with two clearly-labeled paths.
 
 1. **Bundled plugins**: a small set of plugins ships with the framework, in-tree at `plugins/`. These are the reference implementations and the default install (printers, computers, network, equipment, usb, notifications). A site that wants only what's bundled needs no extra work.
 2. **External plugins**: sister sites or third parties build plugins in their own git repos. The site running the framework drops the plugin into `plugins/<name>/` (clone, submodule, or symlink) and runs `flask plugin install <name>`. No pip packaging required for v1.