v0.5.436-rete-plus-develop: fix unknown_origin_location regression on top-level FPFs (#191)

Builds on v0.5.435 with one correctness fix:

- 297dc0b69 fix(rainforest): skip emission on top-level FPFs without resolved location

Closes the unknown_origin_location regression that scaled with recipe
size (cluster: dev 5/8/18/42 vs prod 1/0/2/2 on 4/8/16/40_ings).

Root cause: rainforest's ancestor_flow_location_resolved gate uses
allow_none=True, which lets top-level recipe FPFs through even when
LocationGFM never fires on them (LocationGFM only runs when
flow_location is a raw str; None never qualifies, so a FPF with no
user-specified origin stays at None forever).

Fix extends the existing Origin/WaterScarcity-duplicate skip-if-no-
inheritable-location guard to also cover AddClientNodesGapFillingWorker.

Local repro: combined_4 unknown_origin_location 3 -> 1 (matches develop).
All RETE/GFM unit suites pass (20/20).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>