Final placement mutation reports 0 body overlaps, 0 keepout violations, 0 out-of-bounds components. Read-only DRC reports no findings for body overlap, component outside board, keepout, edge placement, oscillator placement, neckdown escape, pad access, overlapping copper, via-in-pad, invalid layer, missing footprint, or stackup validation in the requested review set. Empty review results are recorded as no reported findings, not proof that every possible manufacturing condition has been tested.

All 71 components remain Top. J1 deliberately overhangs the left edge at its existing edge-placement rule: origin x=-78 mm, rotation 270°, prescribed edge offset 2 mm at x=-80 mm. Its physical body extends to x=-82.55 mm; the edge-connector exemption is intentional, not an off-board placement failure.

Warnings still open: Decoupling Loop Area for C6, C12, C18, C24. C6 and C12 were brought near the corresponding U1 supply pins and their orientations/proximities improved; C24 was moved nearer U4's supply region. The check still reports these advisories but exposes only 'has an issue', not final numeric areas. C18 is the VSYS ADC divider filter, not a supply bypass; review its interpretation before further movement. Route short local ground returns/vias and review these four warnings before final signoff. No placement or neckdown errors remain, but this is not an unqualified all-checks-clean declaration.

Preserved selected Standard Density (SDI) v3, state applied, UID mfp_23e942b5-5c91-4fd8-ad4d-d1d2d3e51999. Reported minimum trace width 0.127 mm, minimum hole 0.25 mm, minimum via diameter 0.55 mm; preferred copper keepout 0.15 mm with minimum 0.127 mm. No profile or rule was loosened.

Preserved selected JLCPCB SDI 4 Layer v1, state applied, UID mfp_promoted_2dd12d2c-0d2e-4294-a994-fa16faefbffc. Final summary confirms four copper layers and unchanged rectangle.

Inspection inconsistency to resolve before controlled-impedance routing: get_layout(mode=stackup) returns 'No stackup configured', while summary reports four copper layers and layout_2d embeds a standard-4-layer physical stackup (~1.30 mm), four Signal copper layers with 0.035 mm copper, two 0.130 mm prepregs above each inner/outer transition and 0.711 mm core. The selected saved target describes two internal ground planes. No physical stackup mutation was made because preservation was required; do not infer actual layer types/reference-plane geometry from the target label alone.

No unlock operation was issued. Scoped component-position actions were used; the placement tool reported no locked-component skip/rejection. The available scene-tree outputs did not enumerate editor lock metadata, so an exhaustive lock UID list cannot be independently certified from those outputs. U1 was intentionally untouched.

No copper edit/routing/deletion tool was called. Initial inspection counted 59 vias; final read-only summary counts 60 vias and one fill. An intervening extra GND via is visible at approximately U2 center (28.002,5.998) mm; attribution is uncertain (tool side effect or concurrent project activity). No via-in-pad finding was reported. Final routing_state reports 124 airwires, zero redundant traces/stale-route groups. Therefore there is no reported stale trace deletion batch; existing ground fill/vias remain for routing review.

Placement is geometrically valid and ready for the next routing phase with the four advisory loop warnings and stackup-inspection uncertainty above. This does not mean the overall PCB is finished: 124 airwires remain and full manufacturing/physical stackup signoff is outstanding.