feat(P1): remove gitea/gitlab from synced files + simplify docs (REQ-230,231,232)

Genericize forge-detection code: gitea→forge/generic_forge, GITEA_ACTOR→FORGE_ACTOR.
Drop .gitea byte-identity test assertions (keep GitHub-side + contract conformance).
Add test_no_forge_mentions.py guard test (REQ-230).
Delete completed migration docs (NOVA_MIGRATION.md, NOVA_AWS_MIGRATION.md).
Move NO_HUMANS_THESIS.md to .ciagent/ (internal artifact).
Strip ciagent-internal provenance from synced docs (REQ-/D-/P-/CAP- IDs,
milestone headers, .ciagent/PROJECT.md citations).
Trim README.md (reusable deploy section, local key rotation paragraph).
Fix version-tag drift (@v1.13→@v1.19, acdl/→nova/).

---ci---
project: acdl
phase: 1
milestone: v1.20
status: execute
requirements: [REQ-230, REQ-231, REQ-232]
---/ci---

mcp/atelier/README.md

@@ -1,9 +1,8 @@
 # Nova Atelier MCP Server
 
-> **v1.18, REQ-223, REQ-224.** An MCP (Model Context Protocol) server that
 > exposes Atelier engineering principles to the citizen developer's AI
-> agent. Plugin-registry architecture (D-140); stdio transport (D-135);
-> vendored Atelier (D-136) for audit reproducibility.
+> agent. Plugin-registry architecture; stdio transport;
+> vendored Atelier for audit reproducibility.
 
 ## What This Is
 
@@ -22,7 +21,7 @@ observability gaps.
 | `atelier.matrix_lookup(domain)` | Look up the domain→core principle mapping for a given domain. |
 | `atelier.validate_against_principles(snippet, domains?)` | Validate a code/diff snippet against the Atelier agent-checklist. Returns pass/fail per check item with the principle citation. |
 
-## Architecture — Plugin Registry (D-140)
+## Architecture — Plugin Registry
 
 ```
 mcp/atelier/
@@ -31,7 +30,7 @@ mcp/atelier/
 │   ├── __init__.py
 │   ├── principles.py       # lookup_principle, list_domains, matrix_lookup
 │   └── validation.py       # validate_against_principles
-├── vendor/                 # pinned Atelier snapshot (D-136)
+├── vendor/                 # pinned Atelier snapshot
 │   ├── VERSION.md           # pinned tag + upgrade instructions
 │   ├── core/first-principles.md
 │   ├── domains/security/first-principles.md
@@ -68,7 +67,7 @@ s.load_plugins()
 result = s.call_tool("atelier_lookup_principle", {"domain": "security", "principle_id": "P4"})
 ```
 
-## Vendoring (D-136)
+## Vendoring
 
 Atelier is vendored under `vendor/` at a pinned tag (`v0.3.6`, see
 `vendor/VERSION.md`). An agentic validation result is only reproducible if