1.1 Phase B: board grown to 155x100 (20mm left), placement for blocks M/N/O

- Outline left edge 80.19->60.19; MH5/MH6 mounting holes cloned to new corners
- Antenna corridor keepout front-left (notched around MH6) + magjack no-pour/no-via zone
- RJ45 J10 + RS-485 P15 + RS-232 P16 on new left edge behind antenna corridor
- W5500 U11 + 25MHz + terminations between jack and P5; 3V3_ETH buck U12/L8/D11
  in the freed P13/H3 gap under the module (low-profile), bulk caps at load
- SC16IS752 U10 serial cluster behind P15/P16; MAX3232 U15, SP3485 U14
- PCF8574 U13 clear of MOD1 pad ring; RGB JST P14 on right edge (freed P3 slot)
- H4 TTL header moved to front edge (was under module, on D5)
- 24V entry block relocated beside P1 (Q10/C10 in P12 lane, D10/DzG1/Rrp1 pocket);
  old cross-board 24V routing ripped for HV24 re-route
- P3/P13/H3 depopulated; J1/J2/DB pad nets updated (ETH SPI, SER_IRQ, LED flip)
- Fix Phase A miss: SC16IS752 pins 13/14 (I2C SCL/SDA) now wired in sch + board
- Placement verified: 190 footprints, 0 courtyard conflicts, 0 corridor intrusions,
  all new nets 2-ended (verify_phase_b.py)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01GSKKes8GsS4YHAMWJ44tCm

03-Architecture-Hardware/kicad/hbox-watchdog-v4.kicad_sch

@@ -38699,4 +38699,44 @@
 		)
 		(uuid "5e01a4c6-2edf-4995-bcc9-ee99ccedf755")
 	)
+	(wire
+		(pts
+			(xy 546.1 147.32) (xy 549.91 147.32)
+		)
+		(stroke
+			(width 0)
+			(type default)
+		)
+		(uuid "e5fc7db0-7fdc-4d51-8578-0321598256ab")
+	)
+	(label "I2C_SCL"
+		(at 546.1 147.32 0)
+		(effects
+			(font
+				(size 1.27 1.27)
+			)
+			(justify left bottom)
+		)
+		(uuid "f867740f-c099-4131-b35e-2a142d58f3fd")
+	)
+	(wire
+		(pts
+			(xy 546.1 149.86) (xy 549.91 149.86)
+		)
+		(stroke
+			(width 0)
+			(type default)
+		)
+		(uuid "2de15692-aa07-44a1-82d2-51419a00051a")
+	)
+	(label "I2C_SDA"
+		(at 546.1 149.86 0)
+		(effects
+			(font
+				(size 1.27 1.27)
+			)
+			(justify left bottom)
+		)
+		(uuid "77d92d4e-5f7d-4eaa-93f7-56bc0ea4547a")
+	)
 )