Research the Fleet Office, and give it one hull

Fleet Offices sit behind a new Berth Authority doctrine. It costs ore and no
research points, deliberately: points come only from conquering a planet,
conquering needs a fleet, and the fleet caps at its opening hull until an
office exists - so pricing the fleet's own gate in them would lock a player
behind a fight that one vessel has to win first. The research unlocks the
STRUCTURE; capacity is still the built, supplied thing #219 made it.

The tree gains a sixth lane for it, so the branch that fleet size vacated is
occupied again rather than reading as a hole.

Also fixes a shape #216 exposed: a stationed transporter drew a hull written
into its own script while a delivered one drew the definition's, and the
transporter's definition declared none at all - so one in flight was an
empty polygon. Both vessels now draw the definition, and a test pins that
the two paths agree. The repair drone had the same fault, off by two units.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019AJMdB7iuHuLFZM1aBu3GD

vessels/TransporterVesselDefinition.tres

@@ -18,6 +18,7 @@ build_time = 9.0
 support_craftable = true
 icon = 12
 glow_color = Color(0.95, 0.55, 0.85, 1)
+hull_points = PackedVector2Array(0, -16, 10, -4, 10, 14, -10, 14, -10, -4)
 capabilities = PackedStringArray("cargo", "transport")
 component_scenes = Array[PackedScene]([ExtResource("2"), ExtResource("3")])
 base_stats = {"max_speed": 690.0, "acceleration": 2025.0, "cargo_capacity": 20.0, "fuel_capacity": 6.0, "fuel_boost": 1.0, "transport_speed": 120.0, "delivery_speed": 180.0}