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/config.rs

@@ -876,8 +876,10 @@ mod tests {
         // what `ANALYSIS_BACKEND` parsed to. `backend` still reflects the raw
         // request (so the override is visible/loggable), but `effective_backend`
         // is the value the daemon actually dispatches through.
-        let mut cfg = AnalysisConfig::default();
-        cfg.backend = AnalysisBackend::Vision;
+        let mut cfg = AnalysisConfig {
+            backend: AnalysisBackend::Vision,
+            ..Default::default()
+        };
         assert_eq!(cfg.effective_backend(), AnalysisBackend::Ocr);
         cfg.backend = AnalysisBackend::Ocr;
         assert_eq!(cfg.effective_backend(), AnalysisBackend::Ocr);