Delete two staticcheck entries whose findings are gone (V-701)

cmd/mavweb/voiceproxy.go writes http.StatusMethodNotAllowed and
http.StatusServiceUnavailable now, so both ST1013 entries were left behind by
the mavweb work and make lint was failing on master before this branch. The
gate fails on a stale entry by design, so the deletion is not optional. The
accepted set is 16.

docs/caveats/dependencies.md

@@ -3,7 +3,7 @@
 ## The analyzers pass against a baseline, not against zero [#701] {#baseline}
 
 Costs: `make lint` and `make deadcode` are wired and green (V-694), but green
-means "nothing new since 2026-08-11". The accepted set is 18 staticcheck
+means "nothing new since 2026-08-11". The accepted set is 16 staticcheck
 findings and 13 unreachable symbols, listed with a reason each in
 `scripts/analyzers/*.baseline`. Three of the unreachable symbols must stay:
 [layering.md](layering.md#deadcode).

scripts/analyzers/staticcheck.baseline

@@ -29,8 +29,6 @@ internal/router/task_phrases.go	SA9009	ineffectual compiler directive due to ext
 cmd/mavwaked/main.go	SA4006	this value of partial is never used
 
 # Cosmetic and mechanical. V-701 sweeps them.
-cmd/mavweb/voiceproxy.go	ST1013	should use constant http.StatusMethodNotAllowed instead of numeric literal 405
-cmd/mavweb/voiceproxy.go	ST1013	should use constant http.StatusServiceUnavailable instead of numeric literal 503
 internal/ipc/client.go	S1016	should convert r (type chatResp) to ChatReply instead of using struct literal
 internal/ipc/server.go	S1016	should convert reply (type ChatReply) to chatResp instead of using struct literal
 internal/memory/behavior_test.go	S1011	should replace loop with obs = append(obs, habitHistory("calendar_event_20260804_standup", time.Tuesday, 10, 0, 3, now)...)