FG3 build-out: six FG3-x sub-process packages + FG3-1 executable

Adds the six FG3 sub-process packages (processes/fg3-1 .. fg3-6) and wires
them into the FG3 (L2) package via `includes`; FG3 version 0.1.0 -> 0.2.0.

FG3-1 (Rēķina/kredītrēķina saņemšana par precēm/pakalpojumiem) is built out
as an executable L4 package:
- bpmn/rekina-sanemsana.bpmn  - 3-lane process (Nodarbinātais / VPC / Iestāde)
- dmn/rekina-parbaude.dmn     - FIRST hit-policy routing decision table
- resources/                 - roles, agent and mappings binding every user
                               task and the decision to a target
- metadata/                  - ownership, lifecycle, policies

FG3-2..FG3-6 are draft composition placeholders (L4) pending executable
build-out.

Validated against the UAPF 2.2.0 schemas (manifest, ownership, lifecycle,
policies, resource-mapping, enterprise index): all includes resolve, no
duplicated executable artifacts, BPMN/DMN well-formed, and all resource
mapping references resolve to real BPMN/DMN element ids.

processes/fg3/uapf.yaml

@@ -3,8 +3,14 @@ id: vk.gramatvediba.fg3
 name: "FG3 — Saistību un izdevumu uzskaite"
 description: "Function group 3 - accounting for liabilities and expenses: supplier data and contract management, receipt and processing of invoices and supporting documents, and business-trip and economic settlements."
 level: 2
-version: 0.1.0
-includes: []
+version: 0.2.0
+includes:
+  - ../fg3-1
+  - ../fg3-2
+  - ../fg3-3
+  - ../fg3-4
+  - ../fg3-5
+  - ../fg3-6
 cornerstones:
   bpmn: false
   dmn: false