feat(library): add Nix flake detection to repair workflow errata step

The errata step now detects flake.nix and offers library job setup via
sparse checkout. Silent when already configured, informational when no
flake is present. Adds quality criterion and bumps version to 1.5.1.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ncrmro

src/deepwork/standard_jobs/deepwork_jobs/AGENTS.md

@@ -64,6 +64,18 @@ Mitigation strategies documented in `define.md`:
 
 The github_outreach `final_report` step had `analyze_repos` as a file input but was missing it from the `dependencies` list. This was caught at workflow start time but could have been caught earlier during the `implement` step. The define step's validation rules already mention this (`from_step must be in dependencies`) but it was missed during creation.
 
+### Repair Workflow: Library Job Detection (v1.5.1)
+
+The errata step now detects Nix flake devshells and offers to set up shared library jobs via sparse checkout. The behavior is tri-state:
+- **Flake with `DEEPWORK_ADDITIONAL_JOBS_FOLDERS` already set**: Silent — no output
+- **Flake exists but no library job config**: Offer setup with flake.nix snippet and sparse checkout commands
+- **No flake.nix**: Brief mention of the Nix devshell option, no detail
+
+Key details:
+- Library jobs are cloned into `.deepwork/upstream/` via `git clone --sparse --filter=blob:none`
+- Users can include/exclude specific jobs via `git sparse-checkout set --cone` / `sparse-checkout add`
+- Full documentation lives in `library/jobs/README.md`
+
 ## Version Management
 
 - Version is tracked in `job.yml`
@@ -72,5 +84,5 @@ The github_outreach `final_report` step had `analyze_repos` as a file input but
 
 ## Last Updated
 
-- Date: 2026-02-06
-- From conversation about: Learn workflow analyzing severe quality review issues in the new_job execution
+- Date: 2026-03-21
+- From conversation about: Adding library job Nix devshell detection to the repair workflow's errata step

src/deepwork/standard_jobs/deepwork_jobs/job.yml

@@ -1,6 +1,6 @@
 # yaml-language-server: $schema=.deepwork/schemas/job.schema.json
 name: deepwork_jobs
-version: "1.5.0"
+version: "1.5.1"
 summary: "Creates and manages multi-step AI workflows. Use when defining, implementing, testing, or improving DeepWork jobs."
 common_job_info_provided_to_all_steps_at_runtime: |
   Core commands for managing DeepWork jobs. These commands help you define new multi-step
@@ -267,3 +267,4 @@ steps:
           "Rules Folder Removed": "`.deepwork/rules/` folder is gone."
           "Rules Job Removed": "`.deepwork/jobs/deepwork_rules/` is gone."
           "MCP Server Entry Removed": "The `deepwork serve` entry is removed from `.mcp.json` (or the file is deleted if empty)."
+          "Library Jobs Offered": "If a flake.nix exists without DEEPWORK_ADDITIONAL_JOBS_FOLDERS, the user was offered library job setup. If no flake.nix exists, the Nix devshell option was mentioned. If already configured, nothing was said."

src/deepwork/standard_jobs/deepwork_jobs/steps/errata.md

@@ -176,7 +176,61 @@ Check for and remove other obsolete files:
 | `.claude/commands/` | Generated commands | Keep (current system) |
 | `.claude/settings.local.json` | Local overrides | Keep (user settings) |
 
-### Step 7: Verify Git Status
+### Step 7: Library Job Access via Nix Dev Shell
+
+Check whether the project uses a Nix flake devshell and whether shared library jobs are configured.
+
+**Detection logic:**
+
+1. Check if `flake.nix` exists in the repo root:
+   ```bash
+   test -f flake.nix && echo "flake found" || echo "no flake"
+   ```
+
+2. **If `flake.nix` exists**, check whether it already sets `DEEPWORK_ADDITIONAL_JOBS_FOLDERS`:
+   ```bash
+   grep -q 'DEEPWORK_ADDITIONAL_JOBS_FOLDERS' flake.nix && echo "already configured" || echo "not configured"
+   ```
+
+3. **If already configured**: Do nothing. No output about library jobs — this is silent.
+
+4. **If `flake.nix` exists but library jobs are NOT configured**: Offer to set it up. Tell the user:
+   > Your project uses a Nix flake. You can access shared DeepWork library jobs by adding a sparse checkout to your shellHook. This keeps library jobs live and up-to-date without copying them into your project.
+
+   Then suggest adding to their `flake.nix` shellHook:
+   ```nix
+   shellHook = ''
+     export REPO_ROOT=$(git rev-parse --show-toplevel)
+
+     # Clone DeepWork library jobs if not present
+     if [ ! -d "$REPO_ROOT/.deepwork/upstream" ]; then
+       git clone --sparse --filter=blob:none \
+         https://github.com/Unsupervisedcom/deepwork.git \
+         "$REPO_ROOT/.deepwork/upstream"
+       git -C "$REPO_ROOT/.deepwork/upstream" sparse-checkout set --cone library/jobs/
+     fi
+
+     export DEEPWORK_ADDITIONAL_JOBS_FOLDERS="$REPO_ROOT/.deepwork/upstream/library/jobs"
+   '';
+   ```
+
+   And adding `.deepwork/upstream/` to `.gitignore`.
+
+   If the user wants only specific library jobs, they can use sparse checkout to include/exclude:
+   ```bash
+   # Check out only specific jobs
+   git -C .deepwork/upstream sparse-checkout set --cone library/jobs/repo/
+
+   # Add more later
+   git -C .deepwork/upstream sparse-checkout add library/jobs/spec_driven_development/
+   ```
+
+5. **If no `flake.nix` exists**: Mention it as an option. Tell the user:
+   > DeepWork library jobs can be accessed via a Nix dev shell with `DEEPWORK_ADDITIONAL_JOBS_FOLDERS`. See `library/jobs/README.md` in the DeepWork repo for setup instructions.
+
+   Do not go into detail — just make the user aware.
+
+### Step 8: Verify Git Status
 
 Check that the cleanup hasn't left untracked garbage: