refactor(clippy): fix the never-loop error and clear all lint warnings

`cargo clippy --all-targets` was failing on a deny-by-default
`never_loop` in the analysis SSE handler (the `loop` always returned on
the first iteration — the stream `unfold` already re-enters per event),
plus ~28 warnings. All resolved with no behaviour change:

- admin/analysis SSE: drop the dead `loop` wrapper.
- app: match port literals directly instead of `if p == 80` guards.
- repo/user: separate doc list from the following paragraphs.
- repo/upload_history: `sort_by_key(Reverse(..))` over `sort_by`.
- crawler/nav test: construct the error directly (no `unwrap_err` on a
  literal `Err`).
- test helpers: build configs via struct-update syntax instead of
  `Default::default()` + field reassignment; add a type alias for a
  complex audit-row tuple.
- plus the mechanical `deref`/etc. fixes from `cargo clippy --fix`.

Note: not running `cargo fmt` — the backend uses a consistent
hand-formatted style that differs from rustfmt-default across ~110
files, so a blanket reformat would be pure churn.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/src/crawler/nav.rs

@@ -164,8 +164,7 @@ mod tests {
 
     #[test]
     fn anyhow_with_nav_timeout_in_chain_is_flagged() {
-        let inner: Result<(), NavError> = Err(NavError::Timeout(NAV_TIMEOUT));
-        let outer = inner.unwrap_err();
+        let outer = NavError::Timeout(NAV_TIMEOUT);
         let wrapped: anyhow::Error =
             anyhow::Error::new(outer).context("wait for chapter nav");
         assert!(anyhow_looks_browser_dead(&wrapped));