Improve Codebase :: Misc

[81reap]

I have started on this path with #1382 but I thought it would be worth creating an issue to track all of the changes I'm thinking about that will come after this. This audit was done with the help of Claude.

Small, independent, and mostly deletions the compiler can verify.

#	Item	Where
E1	Leftover dbg!(&normalized_path, &self.contents); in the routing test store. It prints on every lookup in every routing test. It is the only dbg! in src/.	routing.rs:640
E2	type H0 and impl CanHelp for H0 — no call sites	template_helpers.rs:12, :523-530
E3	impl From<URLParameters> for String — no call sites	url_parameters.rs:130-134
E4	impl ResponseError for ErrorWithStatus — unreachable. Every construction site converts to anyhow::Error immediately, and the status is recovered by downcast at error.rs:212. Its body text never ships.	error_with_status.rs:20-38
E5	impl From<AnyKind> for SupportedDatabase — reachable only through otel_name_from_kind, whose callers all pass a SupportedDatabase. It also maps Odbc → Generic, which contradicts DbInfo::database_type.	database/mod.rs:115-125
E6	strip_site_prefix is a no-op when called from serve_file: routing.rs:169 already stripped the prefix before Serve(path) was built	http.rs:480-482, called at :446
E7	telemetry::shutdown_telemetry() runs only on graceful shutdown. Both std::process::exit(1) paths (main.rs:14, :35) skip it, so traces are lost for exactly the failures traces exist to explain.	main.rs:53
E8	Root test.hurl is orphaned. Both discovery sites use find examples -mindepth 2 -maxdepth 2 -name test.hurl, which cannot match a file at the repository root.	scripts/test-examples-hurl.sh:74, ci.yml:422
E9	.dockerignore:9 excludes mssql/, which does not exist in the repository. .dockerignore:3 excludes sqlpage.db, but Docker anchors that pattern to the root, so sqlpage/sqlpage.db is not excluded and Dockerfile:43 copies it into the image.	.dockerignore
E10	sqlpage.service duplicates ProtectClock=true on lines 42 and 47. Nothing in CI validates the unit file parses.	sqlpage.service