Repo hygiene: fill stack-and-commands, normalize workplan statuses

- Fill .claude/rules/stack-and-commands.md (was an empty TODO template)
- Normalize workplan frontmatter statuses to canonical vocabulary
  (completed/done -> finished) per ADR-001

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

workplans/RAIL-HO-WP-0001-hosteurope-bootstrap.md

@@ -4,7 +4,7 @@ type: workplan
 title: "Secure Single-Server Bootstrap at HostEurope"
 domain: financials
 repo: railiance-infra
-status: completed
+status: finished
 owner: railiance
 topic_slug: railiance
 repo_goal_id: 9e835b82-acca-493a-943f-2553ffe0bf54

workplans/RAIL-HO-WP-0002-server-spec-and-test-suite.md

@@ -4,7 +4,7 @@ type: workplan
 title: "Server Specification and Automated Test Suite"
 domain: financials
 repo: railiance-infra
-status: completed
+status: finished
 owner: railiance
 topic_slug: railiance
 state_hub_workstream_id: "8fed53c2-4c39-4471-8bb9-61f58771fe0c"

workplans/RAIL-HO-WP-0003-5repo-stack-restructure.md

@@ -4,7 +4,7 @@ type: workplan
 title: "Railiance 5-Repo Stack Restructure"
 domain: financials
 repo: railiance-infra
-status: completed
+status: finished
 owner: railiance
 topic_slug: railiance
 state_hub_workstream_id: "3ae0afc5-13f2-4e6c-aea7-1c1fb9f1ab81"