refactor(docs)!: rename CLI binary to corestack-docs

go install names binaries after the directory, so cmd/docs installed an
ambiguous `docs` binary into $GOBIN that could clobber or be clobbered
by other tools. Move it to cmd/corestack-docs, matching corestack-goose,
and update goreleaser, CI, docs and usage text. Accepted ADRs keep their
text and gain a dated rename note.

BREAKING CHANGE: `go install go.auvem.com/corestack/cmd/docs@latest`
stops resolving after the next tag; use cmd/corestack-docs. @v0.1.0
still installs the old `docs` binary.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.goreleaser.yaml

@@ -1,10 +1,10 @@
 version: 2
-project_name: docs
+project_name: corestack-docs
 
 builds:
-  - id: docs
-    main: ./cmd/docs
-    binary: docs
+  - id: corestack-docs
+    main: ./cmd/corestack-docs
+    binary: corestack-docs
     env:
       - CGO_ENABLED=0
     goos: [darwin, linux]
@@ -14,7 +14,7 @@ builds:
 
 archives:
   - formats: [tar.gz]
-    name_template: "docs_{{ .Version }}_{{ .Os }}_{{ .Arch }}"
+    name_template: "corestack-docs_{{ .Version }}_{{ .Os }}_{{ .Arch }}"
 
 checksum:
   name_template: checksums.txt