Add Pretty Table project: plan, accepted documents and code

Business Case, Stakeholder Analysis, Project Plan and milestone MIL-001
with review records RC-001 to RC-003, then the Python project: PrettyTable
Pokemon table, constants, pytest tests, pyproject.toml, Doxyfile, CI
workflow and README.

Task: MIL-001#1
Task: MIL-001#2
Task: MIL-001#3
Task: MIL-001#4
Task: MIL-001#5
Task: MIL-001#6
Task: MIL-001#7
Task: MIL-001#8

.claude/skills/artifact/references/BMC.md

@@ -0,0 +1,21 @@
+# Business Model Canvas (BMC)
+
+Cite in `CrossReference` only if the instance exists (`new-artifact.sh` checks this for you):
+
+- **BC** — Objectives the canvas operationalizes; cost/revenue must agree with its Cost–Benefit Assessment
+- **SA** — Value Propositions, Customer Segments, Channels — cite S-IDs
+- **BPMN** — Key Activities — cite the process that realizes them
+- **KPI** — Measures of value proposition / revenue — cite KPI IDs
+
+## Required sections (after Metadata / Version History)
+
+1. **Purpose / Scope** — one paragraph.
+2. **Canvas** — all 9 building blocks populated, none empty: Key Partners,
+   Key Activities, Key Resources, Value Propositions, Customer
+   Relationships, Channels, Customer Segments, Cost Structure, Revenue
+   Streams. Must stay reviewable as a single, concise overview.
+3. **Assumptions** — explicit and testable (how would we know it is wrong?).
+4. **Consistency Check** — Revenue Streams vs Cost Structure agree;
+   Segments/Channels match stakeholder groups from `SA`.
+
+Cite Business Case objectives (`[BC-001]`) instead of restating them.