mcs150: enrich intake from FMCSA carrier census before PDF fill

The MCS-150 biennial update re-confirms the carrier's existing FMCSA
record. Previously the PDF filler only had whatever the intake form
collected; rescued/sparse orders (or orders where the carrier's data
lives in FMCSA, not the intake) produced near-empty forms. Now we pull
the carrier census (legal name, address, EIN, fleet counts) from the
FMCSA carrier API and merge it under any customer-provided intake values
(customer edits win), so the form is pre-filled with the carrier's
current registered data. Refactored the FMCSA fetch into a shared
_fetch_fmcsa_carrier helper used by both enrichment and status check.

scripts/workers/services/ink_signature_plotter.py

@@ -91,6 +91,85 @@ class PlotterConfig:
     servo_up_angle: int = 90
     # Line-us mapping (only used when dialect == "lineus").
     lineus: "LineUsConfig | None" = None
+    # Pen-specific tuning (ink flow, dwell, line look). See PenProfile / PENS.
+    pen: "PenProfile | None" = None
+
+
+@dataclass(frozen=True)
+class PenProfile:
+    """Per-pen tuning for a writing instrument mounted in the plotter.
+
+    Different pens lay ink differently when the plotter drops the tip STRAIGHT
+    DOWN (no human wrist angle/pressure modulation). Wet gel/rollerball pens read
+    as a genuine signature but need (a) a short dwell at pen-down so the ink wets
+    the paper before the first move (avoids a starting gap), and (b) a slower draw
+    feed so the line lays down evenly without skipping on fast reversals. These
+    values are applied by the emitters on top of the machine PlotterConfig.
+
+    Recommended default for legal filings: uni-ball Signo (UM-151 0.38mm) —
+    archival, waterproof, fraud-resistant gel ink that reads as original wet ink.
+
+      pen_down_dwell_ms : pause after the pen contacts paper, before the first
+                          drawing move, to let wet ink start cleanly (G4 dwell).
+      pen_up_dwell_ms   : brief pause after lifting (lets gel/rollerball tips
+                          "snap" off cleanly without a tail). Usually small/0.
+      draw_feed         : per-pen drawing feed (mm/min). Overrides the machine
+                          default when set; wet pens like ~600-900.
+      pen_down_bias_mm  : small extra downward offset (mm) added to pen_down so a
+                          spring holder keeps positive contact for this tip.
+      tip_mm            : nominal tip width (mm), informational / preview only.
+    """
+    name: str = "uniball-signo"
+    label: str = "uni-ball Signo UM-151 0.38 (gel)"
+    pen_down_dwell_ms: int = 120
+    pen_up_dwell_ms: int = 0
+    draw_feed: float = 750.0
+    pen_down_bias_mm: float = 0.0
+    tip_mm: float = 0.38
+
+
+# Tuned presets for the pens we keep on hand. Default = uni-ball Signo.
+PENS: dict[str, PenProfile] = {
+    "uniball-signo": PenProfile(
+        name="uniball-signo",
+        label="uni-ball Signo UM-151 0.38 (gel, archival/waterproof)",
+        pen_down_dwell_ms=120, pen_up_dwell_ms=0, draw_feed=750.0,
+        pen_down_bias_mm=0.0, tip_mm=0.38,
+    ),
+    "pilot-g2": PenProfile(
+        name="pilot-g2",
+        label="Pilot G-2 0.7 (gel, hand-written look)",
+        # G-2 can blob on a long pen-down dwell; keep dwell short.
+        pen_down_dwell_ms=80, pen_up_dwell_ms=0, draw_feed=800.0,
+        pen_down_bias_mm=0.0, tip_mm=0.7,
+    ),
+    "energel": PenProfile(
+        name="energel",
+        label="Pentel EnerGel 0.5 (liquid-gel, fast-dry batch)",
+        # Liquid-gel starts instantly and dries fast — minimal dwell, faster feed.
+        pen_down_dwell_ms=60, pen_up_dwell_ms=0, draw_feed=900.0,
+        pen_down_bias_mm=0.0, tip_mm=0.5,
+    ),
+    "fountain": PenProfile(
+        name="fountain",
+        label="Fountain pen + document ink (max ink character)",
+        # Fountain nibs need a touch more settle time and a gentle, slower line;
+        # add a small downward bias so the nib keeps consistent flow.
+        pen_down_dwell_ms=180, pen_up_dwell_ms=40, draw_feed=600.0,
+        pen_down_bias_mm=-0.1, tip_mm=0.5,
+    ),
+}
+
+DEFAULT_PEN = "uniball-signo"
+
+
+def load_pen(name: str | None) -> PenProfile:
+    """Return a PenProfile for a named pen (default uni-ball Signo)."""
+    key = (name or DEFAULT_PEN).lower()
+    if key not in PENS:
+        raise ValueError(f"unknown pen '{name}'; choices: {sorted(PENS)}")
+    return PENS[key]
+
 
 
 @dataclass(frozen=True)