docs: Add OSS project files (CHANGELOG, linter config, release docs)

- CHANGELOG.md: Initial release notes for v0.1.0
- .golangci.yml: Linter configuration adapted from beads
- RELEASING.md: Release process documentation

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

.golangci.yml

@@ -0,0 +1,63 @@
+version: "2"
+
+run:
+  timeout: 5m
+  tests: false
+
+linters:
+  default: 'none'
+  enable:
+    - errcheck
+    - gosec
+    - misspell
+    - unconvert
+    - unparam
+
+  settings:
+    errcheck:
+      exclude-functions:
+        - (*database/sql.DB).Close
+        - (*database/sql.Rows).Close
+        - (*database/sql.Tx).Rollback
+        - (*database/sql.Stmt).Close
+        - (*database/sql.Conn).Close
+        - (*os.File).Close
+        - (os).RemoveAll
+        - (os).Remove
+        - (os).Setenv
+        - (os).Unsetenv
+        - (os).Chdir
+        - (os).MkdirAll
+        - (fmt).Sscanf
+    misspell:
+      locale: US
+
+  exclusions:
+    rules:
+      # G304: File inclusion via variable in tests is safe (test data)
+      - path: '_test\.go'
+        linters:
+          - gosec
+        text: "G304"
+      # G306: File permissions 0644 in tests are acceptable (test fixtures)
+      - path: '_test\.go'
+        linters:
+          - gosec
+        text: "G306"
+      # G302/G306: Directory/file permissions 0700/0750 are acceptable
+      - linters:
+          - gosec
+        text: "G302.*0700|G301.*0750"
+      # G204: Safe subprocess launches with validated arguments (tmux, git, etc.)
+      - path: 'internal/tmux/|internal/git/|internal/cmd/'
+        linters:
+          - gosec
+        text: 'G204'
+      # errcheck: Ignore unchecked errors in test files for common cleanup patterns
+      - path: '_test\.go'
+        linters:
+          - errcheck
+        text: "Error return value of .*(Close|Rollback|RemoveAll|Setenv|Unsetenv|Chdir|MkdirAll|Remove|Write).* is not checked"
+
+issues:
+  uniq-by-line: true