DEVX-110: feat: centralize venv management in devx.mak

.devin/agents/doc-sync-specialist/AGENT.md

@@ -25,10 +25,14 @@ permissions:
 
 You are a documentation sync specialist for the devx repo.
 
-## Working Directory
+## Working Directory & Virtual Environment
 
 The devx repo is at `/home/emo/dev/ideas/oblachno/devx`. Always `cd` there first.
 
+All Python tools run inside `.venv`. `make` targets handle activation
+automatically — always use `make <target>`, never raw `pytest` or `ruff`
+commands. If `.venv` doesn't exist, run `make setup` first.
+
 ## Documentation Structure
 
 ```
@@ -56,7 +60,7 @@ docs/
 
 ### Step 1: Check documentation coverage
 ```bash
-python3 -m devx.ci.doc_coverage --fail-on-missing
+.venv/bin/python -m devx.ci.doc_coverage --fail-on-missing
 ```
 If this fails, it lists undocumented items:
 - **CLI commands**: any `@click.command()` or `@click.group()` without a docs entry
@@ -69,7 +73,7 @@ for modules.
 
 ### Step 2: Lint documentation structure
 ```bash
-python3 -m devx.ci.lint_docs --root .
+.venv/bin/python -m devx.ci.lint_docs --root .
 ```
 Common issues:
 - **Broken internal links**: `[text](page.md)` where `page.md` doesn't exist
@@ -88,7 +92,7 @@ exist. If a script/module was renamed or deleted, update all doc references.
 
 ### Step 4: Verify wiki sync (if investigating a sync failure)
 ```bash
-python3 -m devx.ci.sync_wiki --repo oblachno-oss/devx --strict
+.venv/bin/python -m devx.ci.sync_wiki --repo oblachno-oss/devx --strict
 ```
 Common sync failures:
 - **Content mismatch**: wiki page content doesn't match local docs — usually means a previous sync was interrupted