docs: changelog missing entries for most PRs merged in the #2312-#2407 range #2409

Is your feature request related to a problem? Please describe.

docs/source/changelog/1.5.0.rst has no entry for most PRs merged in the #2312–#2407 range. Confirmed independently twice this round (the #1103 sweep worker and its cross-review): of the PRs in that range, only #2334, #2336, #2337, #2340 and #2348 added changelog entries (all but #2334 are ! breaking changes), and #2398/#2403 only reworded existing lines. The rest — including user-visible work like #2393/#2401 (str-enum-name resolution), #2383 (HIP parameters=), #2395 (httpv2 default), and #2296/#2404/#2405/#2407 (maker error messages) — have no entry by PR or issue number.

Describe the solution you'd like

A dedicated pass adding 1.5.0.rst entries for the user-visible PRs in this range, per the PR template's own rule ("changelog entry if the change is user-visible"). Per #719's established scope, this is its own PR — not folded into a prose sweep or #657.

Describe alternatives you've considered

Folding it into #2408 (the current #1103 sweep PR) was rejected — that PR is prose-only per #719's rules, and a changelog backfill spanning dozens of PRs needs its own review.