config: migrate gomodguard to gomodguard_v2 in canonical .golangci.yml

golangci-lint v2.12.0 deprecated `gomodguard` in favour of `gomodguard_v2`.
Because the canonical config uses `default: all`, the deprecated linter is
auto-enabled and every lint run in every consuming Go repo emits a
deprecation warning.

`gomodguard` and `gomodguard_v2` are two independently registered linters
in v2.12.2, so `gomodguard_v2` is already enabled by `default: all`; only
the deprecated one needs disabling. This mirrors the existing `wsl` entry,
which was disabled for the same reason when `wsl_v5` superseded it.

No settings migration was required: the canonical config configures no
gomodguard settings at all.

Refs: #25

.golangci.yml

@@ -16,6 +16,7 @@ linters:
     - depguard         # Dependency allow/block lists
     - godot            # Requires comments to end with periods
     - wsl              # Deprecated, replaced by wsl_v5
+    - gomodguard       # Deprecated, replaced by gomodguard_v2
     - wrapcheck        # Too verbose for internal packages
     - varnamelen       # Short names like db, id are idiomatic Go
   settings:

TODO.md

@@ -21,9 +21,6 @@ fmt-check, and commit.
 
 # Completed Steps
 
-- 2026-08-10: Added `-count=1` to both `go test` invocations in the canonical Go
-  `make test` example in `REPO_POLICIES.md`, so the target cannot report a
-  cached pass it did not earn.
 - 2026-08-07: Set the canonical `.golangci.yml` to the org-standard v2-schema
   config already deployed byte-identical across the org's Go repos (settings
   under `linters.settings` so thresholds like lll/funlen/cyclop/dupl actually

prompts/REPO_POLICIES.md

@@ -1,6 +1,6 @@
 ---
 title: Repository Policies
-last_modified: 2026-08-10
+last_modified: 2026-08-07
 ---
 
 This document covers repository structure, tooling, and workflow standards. Code
@@ -209,16 +209,11 @@ style conventions are in separate documents:
 
     ```makefile
     test:
-    	@go test -count=1 -timeout 30s -race -cover ./... || \
+    	@go test -timeout 30s -race -cover ./... || \
     		{ echo "--- Rerunning with -v for details ---"; \
-    		  go test -count=1 -timeout 30s -race -v ./...; exit 1; }
+    		  go test -timeout 30s -race -v ./...; exit 1; }
     ```
 
-    `-count=1` is required on both invocations: it defeats Go's test _result_
-    cache, so the target cannot report a pass it did not earn, and the rerun
-    reproduces a failure instead of replaying it. It leaves the build cache
-    alone, so it costs the runtime of the suite and no recompilation.
-
     Python example:
 
     ```makefile