chore: remove redundant export-only tests, add test audit procedure

Deleted chat_editor_test.exs and import_editor_test.exs which only
checked function_exported?/Code.ensure_loaded? without exercising any
behavior — both components are already tested via LiveView rendering
in shell_live_test.exs and import_shell_live_test.exs respectively.

Added TESTAUDIT.md documenting the procedure for periodic test suite
audits to catch non-behavioral tests.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

TESTAUDIT.md

@@ -0,0 +1,87 @@
+# Test Audit Procedure
+
+Periodic review of the unit test suite to ensure every test exercises production
+code against real assumptions and behavior.
+
+## Scope
+
+All `*_test.exs` files under `test/`.
+
+## What counts as a valid unit test
+
+A valid unit test **calls at least one production function** from `lib/bds/` and
+**asserts on its return value, side effects, or observable behavior**.
+
+Acceptable patterns:
+
+- Calling a production function and asserting its return value.
+- Calling a production function with injected test doubles (fake HTTP clients,
+  fake runtimes) and asserting the production code's orchestration logic.
+- Mounting a LiveView or rendering a LiveComponent and asserting HTML output
+  or database state after interactions.
+- Sending events to a GenServer and asserting state transitions.
+
+### Source-property tests (acceptable, not flagged)
+
+Tests that verify structural properties of source code are acceptable and should
+not be flagged during this audit. Examples:
+
+- Checking that all public functions have `@spec` annotations (AST parsing).
+- Asserting absence of `String.to_atom` or `cond do` in specific files.
+- Verifying CSS/JS/template assets contain expected class names or imports.
+- Checking that `API.md` matches the output of a documentation generator.
+- Verifying database indexes exist via `EXPLAIN QUERY PLAN`.
+- Asserting `.allium` spec files have consistent parameter signatures.
+- Checking config files for expected values.
+- Verifying function decomposition patterns in source.
+
+These are linting/contract/consistency checks. They serve a purpose but are
+distinct from behavioral tests.
+
+## What gets flagged
+
+1. **Export-existence-only tests** — tests that call `function_exported?/3` or
+   `Code.ensure_loaded?/1` without ever invoking the function. These verify
+   compilation, not behavior. They are redundant when the same module is already
+   tested via rendering or direct calls in another test file.
+
+2. **Mock-only tests** — tests that define a fake/stub module and only assert
+   on that fake's behavior without routing through any production code path.
+
+3. **Trivially-passing tests** — tests whose assertions succeed regardless of
+   whether the production code is correct (e.g., asserting on a hardcoded value
+   that never touches production logic).
+
+## How to run the audit
+
+Ask Claude Code to:
+
+> Analyse the unit tests of the project and check if all of them actually call
+> proper production code or if there are tests that essentially only test
+> scaffolds, mocks and helper functions. Every unit test must test proper
+> production code against assumptions and behaviour. Source-property tests
+> (structure, @spec, asset presence, schema verification, doc staleness) are
+> acceptable and should not be flagged.
+
+The audit should:
+
+1. Read every `*_test.exs` file under `test/` in full.
+2. For each test block, identify which production function (if any) is called.
+3. Flag any test that falls into the categories above.
+4. Report flagged tests with file path, line number, and explanation.
+
+## Audit log
+
+### 2026-05-11
+
+Reviewed all 71 test files (69 after cleanup). Found 2 redundant files:
+
+- `test/bds/desktop/shell_live/chat_editor_test.exs` — single test only called
+  `function_exported?` for `ChatEditor`. The component was already fully tested
+  via `render_component` in `shell_live_test.exs`. **Deleted.**
+
+- `test/bds/desktop/shell_live/import_editor_test.exs` — single test only called
+  `Code.ensure_loaded?` + `function_exported?` for `ImportEditor`. The component
+  was already exercised in `import_shell_live_test.exs`. **Deleted.**
+
+Result after cleanup: 646 tests, 0 failures, 4 skipped.