Rename all arch references to plano across the codebase

Complete rebrand from "Arch"/"archgw" to "Plano" including:
- Config files: arch_config_schema.yaml, workflow, demo configs
- Environment variables: ARCH_CONFIG_* → PLANO_CONFIG_*
- Python CLI: variables, functions, file paths, docker mounts
- Rust crates: config paths, log messages, metadata keys
- Docker/build: Dockerfile, supervisord, .dockerignore, .gitignore
- Docker Compose: volume mounts and env vars across all demos/tests
- GitHub workflows: job/step names
- Shell scripts: log messages
- Demos: Python code, READMEs, VS Code configs, Grafana dashboard
- Docs: RST includes, code comments, config references
- Package metadata: package.json, pyproject.toml, uv.lock

External URLs (docs.archgw.com, github.com/katanemo/archgw) left as-is.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.github/workflows/e2e_plano_tests.yml

@@ -28,7 +28,7 @@ jobs:
           python-version: ${{ matrix.python-version }}
           cache: "pip"  # auto-caches based on requirements files
 
-      - name: build arch docker image
+      - name: build plano docker image
         run: |
           cd ../../ && docker build -f Dockerfile . -t katanemo/plano -t katanemo/plano:0.4.6 -t katanemo/plano:latest
 

.github/workflows/e2e_test_currency_convert.yml

@@ -38,7 +38,7 @@ jobs:
           curl --location --remote-name https://github.com/Orange-OpenSource/hurl/releases/download/4.0.0/hurl_4.0.0_amd64.deb
           sudo dpkg -i hurl_4.0.0_amd64.deb
 
-      - name: install arch gateway and test dependencies
+      - name: install plano gateway and test dependencies
         run: |
           source venv/bin/activate
           cd cli && echo "installing plano cli" && uv sync && uv tool install .

.github/workflows/e2e_test_preference_based_routing.yml

@@ -22,7 +22,7 @@ jobs:
         with:
           python-version: "3.12"
 
-      - name: build arch docker image
+      - name: build plano docker image
         run: |
           docker build  -f Dockerfile . -t katanemo/plano -t katanemo/plano:0.4.6
 
@@ -38,7 +38,7 @@ jobs:
           curl --location --remote-name https://github.com/Orange-OpenSource/hurl/releases/download/4.0.0/hurl_4.0.0_amd64.deb
           sudo dpkg -i hurl_4.0.0_amd64.deb
 
-      - name: install arch gateway and test dependencies
+      - name: install plano gateway and test dependencies
         run: |
           source venv/bin/activate
           cd cli && echo "installing plano cli" && uv sync && uv tool install .

.github/workflows/validate_plano_config.yml

@@ -1,4 +1,4 @@
-name: arch config tests
+name: plano config tests
 
 on:
   push:
@@ -7,7 +7,7 @@ on:
   pull_request:
 
 jobs:
-  validate_arch_config:
+  validate_plano_config:
     runs-on: ubuntu-latest
     defaults:
       run:
@@ -22,10 +22,10 @@ jobs:
         with:
           python-version: "3.12"
 
-      - name: build arch docker image
+      - name: build plano docker image
         run: |
           docker build  -f Dockerfile . -t katanemo/plano -t katanemo/plano:0.4.6
 
-      - name: validate arch config
+      - name: validate plano config
         run: |
           bash config/validate_plano_config.sh