docs: anchor the product-doc citations to symbols, not line numbers

Ten more were already pointing at unrelated code. Vendor SDK and SWELL citations left alone — those files don't move.

docs/product/render-in-place.md

@@ -199,7 +199,7 @@ it — three small pure additions and one bounded seam:
 
 1. **A render destination that is not the bank.** `OfflineRenderBackend::capture`
    derives its output path from `deriveBankPaths(projectDir, …)` unconditionally
-   (`capture.cpp:417`) and points `RENDER_FILE` at the bank folder. Nothing about
+   (`capture.cpp`'s `OfflineRenderBackend::capture`) and points `RENDER_FILE` at the bank folder. Nothing about
    that is parameterized. The alternative — render into the bank and then move the
    file out — was rejected: it puts a transient, unindexed, unowned file inside the
    folder prune enumerates, which is exactly the file class the ownership rule exists