docs: update plan status and move completed nats-deploy plan

- Move nats-deploy-service.md to completed/ folder
- Update prometheus-scrape-target-labels.md with implementation status
- Add status table showing which steps are complete/partial/not started
- Update cross-references to point to new location

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docs/plans/prometheus-scrape-target-labels.md

@@ -1,10 +1,32 @@
 # Prometheus Scrape Target Labels
 
+## Implementation Status
+
+| Step | Status | Notes |
+|------|--------|-------|
+| 1. Create `homelab.host` module | ✅ Complete | `modules/homelab/host.nix` |
+| 2. Update `lib/monitoring.nix` | ❌ Not started | Labels not extracted or propagated |
+| 3. Update Prometheus config | ❌ Not started | Still uses flat target list |
+| 4. Set metadata on hosts | ⚠️ Partial | Some hosts configured, see below |
+| 5. Update alert rules | ❌ Not started | |
+| 6. Labels for service targets | ❌ Not started | Optional |
+
+**Hosts with metadata configured:**
+- `ns1`, `ns2`: `role = "dns"`, `labels.dns_role = "primary"/"secondary"`
+- `nix-cache01`: `role = "build-host"` (missing `priority = "low"` from plan)
+- `vault01`: `role = "vault"`
+- `jump`: `role = "bastion"`
+- `template`, `template2`, `testvm*`: `tier` and `priority` set
+
+**Key gap:** The `homelab.host` module exists and some hosts use it, but `lib/monitoring.nix` does not extract these values—they are not propagated to Prometheus scrape targets.
+
+---
+
 ## Goal
 
 Add support for custom per-host labels on Prometheus scrape targets, enabling alert rules to reference host metadata (priority, role) instead of hardcoding instance names.
 
-**Related:** This plan shares the `homelab.host` module with `docs/plans/nats-deploy-service.md`, which uses the same metadata for deployment tier assignment.
+**Related:** This plan shares the `homelab.host` module with `docs/plans/completed/nats-deploy-service.md`, which uses the same metadata for deployment tier assignment.
 
 ## Motivation
 
@@ -54,12 +76,11 @@ or
 
 ## Implementation
 
-This implementation uses a shared `homelab.host` module that provides host metadata for multiple consumers (Prometheus labels, deployment tiers, etc.). See also `docs/plans/nats-deploy-service.md` which uses the same module for deployment tier assignment.
+This implementation uses a shared `homelab.host` module that provides host metadata for multiple consumers (Prometheus labels, deployment tiers, etc.). See also `docs/plans/completed/nats-deploy-service.md` which uses the same module for deployment tier assignment.
 
 ### 1. Create `homelab.host` module
 
-**Status:** Step 1 (Create `homelab.host` module) is complete. The module is in
+✅ **Complete.** The module is in `modules/homelab/host.nix`.
-`modules/homelab/host.nix` with tier, priority, role, and labels options.
 
 Create `modules/homelab/host.nix` with shared host metadata options:
 
@@ -98,6 +119,8 @@ Import this module in `modules/homelab/default.nix`.
 
 ### 2. Update `lib/monitoring.nix`
 
+❌ **Not started.** The current implementation does not extract `homelab.host` values.
+
 - `extractHostMonitoring` should also extract `homelab.host` values (priority, role, labels).
 - Build the combined label set from `homelab.host`:
 
@@ -126,6 +149,8 @@ This requires grouping hosts by their label attrset and producing one `static_co
 
 ### 3. Update `services/monitoring/prometheus.nix`
 
+❌ **Not started.** Still uses flat target list (`static_configs = [{ targets = nodeExporterTargets; }]`).
+
 Change the node-exporter scrape config to use the new structured output:
 
 ```nix
@@ -138,29 +163,34 @@ static_configs = nodeExporterTargets;
 
 ### 4. Set metadata on hosts
 
+⚠️ **Partial.** Some hosts configured (see status table above). Current `nix-cache01` only has `role`, missing the `priority = "low"` suggested below.
+
 Example in `hosts/nix-cache01/configuration.nix`:
 
 ```nix
 homelab.host = {
-  tier = "test";       # can be deployed by MCP (used by homelab-deploy)
   priority = "low";    # relaxed alerting thresholds
   role = "build-host";
 };
 ```
 
+**Note:** Current implementation only sets `role = "build-host"`. Consider adding `priority = "low"` when label propagation is implemented.
+
 Example in `hosts/ns1/configuration.nix`:
 
 ```nix
 homelab.host = {
-  tier = "prod";
-  priority = "high";
   role = "dns";
   labels.dns_role = "primary";
 };
 ```
 
+**Note:** `tier` and `priority` use defaults ("prod" and "high"), which is the intended behavior. The current ns1/ns2 configurations match this pattern.
+
 ### 5. Update alert rules
 
+❌ **Not started.** Requires steps 2-3 to be completed first.
+
 After implementing labels, review and update `services/monitoring/rules.yml`:
 
 - Replace instance-name exclusions with label-based filters (e.g. `{priority!="low"}` instead of `{instance!="nix-cache01.home.2rjus.net:9100"}`).
@@ -170,4 +200,6 @@ Specifically, the `high_cpu_load` rule currently has a nix-cache01 exclusion tha
 
 ### 6. Consider labels for `generateScrapeConfigs` (service targets)
 
+❌ **Not started.** Optional enhancement.
+
 The same label propagation could be applied to service-level scrape targets. This is optional and can be deferred -- service targets are more specialized and less likely to need generic label-based filtering.