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---

pipelines/README.md

@@ -2,7 +2,7 @@
 
 ## Overview
 
-Nova uses declarative pipeline contracts (YAML) as the single source of truth. Both Gitea and GitHub workflows implement the same contract (byte-identical). The shell runner (`scripts/run_ci.sh`) mirrors the CI pipeline locally so that every stage that runs in CI can be reproduced on a developer machine without a forge.
+Nova uses declarative pipeline contracts (YAML) as the single source of truth. GitHub workflows implement the same contract (byte-identical across forges). The shell runner (`scripts/run_ci.sh`) mirrors the CI pipeline locally so that every stage that runs in CI can be reproduced on a developer machine without a forge.
 
 ## Existing Pipelines
 
@@ -20,7 +20,7 @@ Nova uses declarative pipeline contracts (YAML) as the single source of truth. B
 
 ## How to Wire a Pipeline
 
-1. Create byte-identical workflow YAMLs in `.gitea/workflows/<name>.yml` and `.github/workflows/<name>.yml`.
+1. Create the workflow YAML in `.github/workflows/<name>.yml`.
 2. Both workflows must implement the same stages, commands, triggers, and runner declared in the contract.
 3. `scripts/run_ci.sh` mirrors `ci.yml` locally so the same stages run without a forge.
 4. Consumer repos reference the deploy pipeline via `uses: acdl/.github/workflows/deploy.yml@vX.Y`.
@@ -29,17 +29,17 @@ Nova uses declarative pipeline contracts (YAML) as the single source of truth. B
 
 - `scripts/run_ci.sh` — local CI mirror that runs the `ci.yml` stages.
 - `scripts/run_platform.sh` — platform pipeline runner that implements the `contract.yml` stages.
-- Workflow YAMLs in `.gitea/workflows/` and `.github/workflows/`.
+- Workflow YAMLs in `.github/workflows/`.
 - Schemas in `schemas/` (`pipeline.schema.json`, `deploy-pipeline.schema.json`).
 
 ## How to Test Pipelines
 
-- `tests/test_pipeline_contract.py` — validates each pipeline YAML against its schema, asserts workflow conformance (byte-identical Gitea/GitHub workflows with the same stages/commands/triggers), and tests `scripts/run_ci.sh` execution against the contract.
+- `tests/test_pipeline_contract.py` — validates each pipeline YAML against its schema, asserts workflow conformance (byte-identical workflows with the same stages/commands/triggers), and tests `scripts/run_ci.sh` execution against the contract.
 
 ## Adding a New Pipeline
 
 1. Create `pipelines/<name>.yml` using the structure above.
 2. Create or extend the schema in `schemas/` for the new pipeline shape.
-3. Create byte-identical workflow YAMLs in `.gitea/workflows/<name>.yml` and `.github/workflows/<name>.yml`.
+3. Create the workflow YAML in `.github/workflows/<name>.yml`.
 4. Extend `scripts/run_ci.sh` if a local mirror of the new pipeline is needed.
 5. Write or extend tests in `tests/test_pipeline_contract.py` to assert schema validity and workflow conformance.

pipelines/ci.yml

@@ -1,7 +1,7 @@
 # Nova Central CI Pipeline Contract (v1.5)
 #
 # This is the single source of truth for the CI/CD pipeline. Both
-# .gitea/workflows/ci.yml (Gitea Actions, dev) and
+# .github/workflows/ci.yml (dev) and
 # .github/workflows/ci.yml (GitHub Actions, production) implement the
 # stages, commands, triggers, and runner declared here.
 # scripts/run_ci.sh mirrors the same stages for shell reproducibility.
@@ -11,7 +11,7 @@
 #
 # The contract does NOT replace workflow YAML syntax — it declares the
 # *intent* that the forge-specific workflows implement. The workflow files
-# use Gitea/GitHub Actions syntax (checkout, setup-python, run blocks);
+# use GitHub Actions syntax (checkout, setup-python, run blocks);
 # this contract declares what those blocks must contain.
 #
 # Validated against schemas/pipeline.schema.json.

pipelines/contract.yml

@@ -12,7 +12,7 @@
 #
 # This file is the declarative pipeline spec (a contract, not an executable
 # workflow). The executable workflow is .github/workflows/deploy.yml
-# (GitHub Actions) / .gitea/workflows/deploy.yml (Gitea Actions), which
+# (GitHub Actions), which
 # implements these stages by invoking scripts/run_platform.sh.
 #
 # Validated against schemas/deploy-pipeline.schema.json.

pipelines/modules-lifecycle.yml

@@ -18,8 +18,8 @@ name: acdl-modules-lifecycle
 # real apply→modify→destroy against live AWS. The CI VPC apply/destroy
 # jobs are skipped in plan mode (nothing is applied).
 #
-# Both Gitea (.gitea/workflows/modules-lifecycle.yml) and GitHub
-# (.github/workflows/modules-lifecycle.yml) implement this contract
+# GitHub
+# (.github/workflows/modules-lifecycle.yml) implements this contract
 # byte-identically.
 
 triggers: