fix(skills): add git history regression checks to iteration and diagnosis skills

Agentic iteration loops lack git history context and can re-introduce
patterns that were previously removed for good reasons (e.g. cy.reload()
breaking dynamic plugin chunk loading). This caused a real regression
during the OBSINTA-1290 consolidation.

Added checks to three skills:
- productize-iterations: Step 3 now flags REGRESSIVE overlaps where an
  iteration branch re-introduces a removed pattern
- iterate-incident-tests: Fix Guidelines now require checking git log
  before applying any fix
- diagnose-test-failure: Diagnosis output now includes a History Check
  section that flags previously reverted patterns

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

Author: Claude Agent

.claude/commands/cypress/test-iteration/diagnose-test-failure.md

@@ -128,9 +128,17 @@ Output your diagnosis in this exact format:
 - Change: [specific description of what to change]
 - [If multiple files need changing, list each]
 
+**History Check**:
+- Run `git log origin/main -- <file>` for each file in the recommended fix
+- Look for prior commits that removed or replaced the pattern being proposed
+- If found, note: "WARNING: commit <sha> removed this pattern because <reason>"
+- Example: cy.reload() was removed from prepareIncidentsPageForSearch in e8d0007
+  because it breaks dynamic plugin chunk loading. Do NOT re-introduce it.
+
 **Risk Assessment**:
 - Will this fix affect other tests? [yes/no and why]
 - Could this mask a real bug? [yes/no and why]
+- Does this fix re-introduce a previously reverted pattern? [yes/no]
 
 **Alternative Hypotheses**:
 - [If confidence is MEDIUM or LOW, list other possible causes]

.claude/commands/cypress/test-iteration/iterate-incident-tests.md

@@ -302,6 +302,14 @@ You must NOT edit:
 - If fixing a fixture, validate it against the fixture schema
   (run /cypress:test-development:validate-incident-fixtures mentally or reference the schema)
 - If adding a page object method, follow existing naming conventions
+- **Before applying any fix, check git history** for the file being changed:
+  `git log origin/main -- <file>` — look for prior commits that explicitly
+  removed or replaced the pattern you are about to introduce. For example,
+  `cy.reload()` was previously removed from prepareIncidentsPageForSearch
+  because it breaks dynamic plugin chunk loading in headless CI. The iteration
+  agent lacks git history context and will re-discover "fixes" that were
+  already tried and reverted. If a prior commit removed the pattern for a
+  documented reason, do NOT re-introduce it.
 ```
 
 After the Fix Agent returns, verify the fix makes sense:

.claude/commands/cypress/test-iteration/productize-iterations.md

@@ -86,6 +86,20 @@ Also check for cross-file dependencies:
 - Does branch A add a function that branch B calls?
 - Does branch A change a signature that branch B depends on?
 
+**Critical: Check git history for reverted patterns.** For each changed file, run
+`git log origin/main -- <file>` and read recent commit messages. Look for
+patterns where a prior commit explicitly removed or replaced something that the
+iteration branch is re-introducing. Common examples:
+- `cy.reload()` removed in favor of SPA navigation (dynamic plugin chunk loading
+  breaks on full page reload)
+- Flattened selectors replaced with grouped selectors
+- Timeouts adjusted for a specific reason
+
+If an iteration branch re-introduces a pattern that was previously removed, flag
+it as **REGRESSIVE** and investigate whether the original removal reason still
+applies. The iteration agent doesn't have git history context and will often
+re-discover a "fix" that was already tried and reverted.
+
 Produce an evaluation report:
 ```
 ## Overlap Analysis