docs: add PR work handover document

Comprehensive handover tracking:
- Original problem statement (PR #179 stuck)
- Full plan with 4 phases
- Action to date (3 PRs pushed/ready)
- Action going forward (next 3 branches + guidelines)
- Status table and next-session checklist

This document serves as the source of truth for PR work state
and continuation instructions for future sessions.

Author: petercorke

HANDOVER.md

@@ -0,0 +1,223 @@
+# Spatialmath-Python PR Work Handover
+
+**Last Updated:** 2026-07-27  
+**Status:** PR-A, PR-B pushed; PR-C (fix/twist-pitch-clean) ready; 3 branches pending
+
+---
+
+## Original Problem
+
+PR #179 (fix/base-plot-box) was stuck since April 13, 2026, due to:
+- Python 3.8 test failures (Python 3.8 is EOL; removed from CI)
+- Sphinx documentation build warnings (orphaned doc files, bad reST syntax)
+- Merged work from a large mixed-concern "doco-fix" branch was intertwined with other changes
+
+**User Context:** Returned from focus on other toolboxes (RTB, MVTB, bdsim), needed to catch up on stalled RAI work and prepare clean, focused PRs for review by Jenny Barry (jbarry-bdai).
+
+---
+
+## Plan (Established Session 1)
+
+### Phase 1: Unblock PR #179
+- ✅ **Done:** Rebased PR #179 onto `upstream/master` (commit a82fb08)
+- ✅ **Result:** CLEAN merge state; CI tests pass (13/13 graphics tests)
+- Status: Ready for Jenny to merge
+
+### Phase 2: Split Mixed "doco-fix" Branch into Focused PRs
+The original `doco-fix` branch contained 29 files changed across multiple concerns:
+- Function exports & renames (tr2pos2, pos2tr2, tr2adjoint2)
+- Deprecation of tradjoint2 → tr2adjoint2 with backward compatibility
+- Sphinx docstring formatting fixes (19 files)
+- CI config changes & README updates
+
+**Split Strategy:**
+- **PR-A:** `fix/export-base-functions` — function exports + deprecation alias
+- **PR-B:** `docs/sphinx-docstring-fixes` — docstring fixes, orphaned file cleanup
+- **Other branches:** Process remaining local branches as bite-sized focused PRs
+
+### Phase 3: Clean Remaining Branches
+Create fresh branches from `upstream/master` for:
+- fix/twist-pitch (currently has CI config noise mixed in)
+- new-imatmul
+- norm-fix
+- printline-fix
+- pyproject-black (config only, may be low priority)
+
+### Phase 4: Conventional Commits
+All future PRs use conventional commits:
+```
+type(scope): subject
+
+detailed body
+```
+Examples: `fix(base):`, `feat(twist):`, `docs:`, `refactor:`, `chore:`
+
+---
+
+## Action to Date (Session 2: 2026-07-27)
+
+### ✅ PR-A: fix/export-base-functions
+- **Branch:** `fix/export-base-functions`
+- **Commit:** 40fad13
+- **Changes:**
+  - Export 3 functions: `pos2tr2`, `tr2pos2`, `tr2adjoint2`
+  - Rename: `tradjoint2` → `tr2adjoint2` (naming consistency with 3D `tr2adjoint`)
+  - Add deprecated alias `tradjoint2` with `DeprecationWarning` (version 1.1.16)
+  - Update tests: renamed test, added deprecation warning test
+- **Tests:** 19/19 transforms2d tests pass ✅
+- **Status:** Pushed to origin; **waiting for PR creation to RAI** (was having gh CLI issues)
+
+### ✅ PR-B: docs/sphinx-docstring-fixes
+- **Branch:** `docs/sphinx-docstring-fixes`
+- **Commit:** d4f56bf
+- **Changes:**
+  - Fixed LaTeX escaping in docstrings (missing braces, convert to raw strings)
+  - Corrected reST indentation (documentation lists, note blocks)
+  - Fixed code example imports (e.g., `trnorm` → `trnorm2`, `math.pi` → `np.pi`)
+  - Updated cross-references (`:meth:`, `~seealso:` format)
+  - Fixed parameter name refs (e.g., `S` → `s` in docstrings)
+  - Added missing type annotations in parameter docs
+  - **Deleted** orphaned doc files: `docs/source/classes-2d.rst`, `docs/source/classes-3d.rst`
+  - 18 files modified (19 if counting deleted)
+- **Status:** Pushed to origin; **PR created to RAI** (by user)
+
+### ✅ PR-C: fix/twist-pitch-clean
+- **Branch:** `fix/twist-pitch-clean` (created fresh from `upstream/master`)
+- **Commit:** beef079
+- **Changes:**
+  - Added missing denominator in Twist3.pitch calculation
+  - Before: `return np.dot(self.w, self.v)`
+  - After: `return np.dot(self.w, self.v) / np.dot(self.w, self.w)`
+  - Formula: `pitch = (w · v) / (w · w)` — translation per radian along screw axis
+- **Tests:** 25/25 twist tests pass ✅
+- **Status:** Pushed to origin; **ready for PR creation**
+- **Note:** Original `fix/twist-pitch` branch had noise (CI config, README); this is clean
+
+---
+
+## Action Going Forward
+
+### Immediate (Next Session)
+1. **PR-A & PR-B:** Monitor RAI review feedback (tag jbarry-bdai on PRs if not already done)
+2. **PR-C:** Create PR to RAI for `fix/twist-pitch-clean`
+3. **Cleanup:** Delete old noisy branches locally:
+   - `doco-fix` (content split into PR-A & PR-B)
+   - `fix/twist-pitch` (replaced by fix/twist-pitch-clean)
+   - Any others with mixed concerns
+
+### Phase: Next 3 Branches (Create Fresh from upstream/master)
+
+#### PR-D: new-imatmul (feat/matrix in-place multiplication)
+- **Current branch:** `new-imatmul` (4729fbf)
+- **Expected scope:** Add `@=` operator for SO2, SE2, SO3, SE3 with in-place mult + normalization
+- **Action:**
+  1. Create fresh `feat/imatmul` from `upstream/master`
+  2. Apply ONLY the operator/class changes (exclude any config/CI noise)
+  3. Test all matrix/pose classes
+  4. Commit: `feat(pose,matrix): add @= operator with normalization`
+  5. Push & create PR
+
+#### PR-E: printline-fix (Consistent string representation)
+- **Current branch:** `printline-fix` (9dc38f9)
+- **Expected scope:** Consistent `printline()` method for SO2, SE2, SO3, SE3, Quaternion, UnitQuaternion
+- **Action:**
+  1. Create fresh `refactor/printline` from `upstream/master`
+  2. Apply formatting/base functions for line-string conversion
+  3. Test all pose/quaternion classes
+  4. Commit: `refactor: consistent printline() across pose and quaternion classes`
+  5. Push & create PR
+
+#### PR-F: norm-fix (Rotation matrix normalization)
+- **Current branch:** `norm-fix` (90d41de) — **marked WIP**
+- **Expected scope:** Ensure rotation matrices normalized by default on SO2/SE2/SO3/SE3 creation
+- **⚠️ Investigation needed:**
+  - Determine if this is feature-complete or truly WIP
+  - Check test coverage
+  - Verify no breaking changes to existing tests
+- **Action:**
+  1. Evaluate completeness; if WIP, may defer until Jenny reviews
+  2. If complete: create fresh `feat/normalize-rotations` from `upstream/master`
+  3. Apply changes, test thoroughly
+  4. Commit: `feat(pose): normalize rotation matrices on construction`
+  5. Push & create PR (or flag for later if investigation shows issues)
+
+### Lower Priority (Optional)
+
+#### PR-G: pyproject-black (Config)
+- **Current branch:** `pyproject-black` (1915b9d)
+- **Scope:** Configure black to use version 23 for consistency
+- **Status:** Config-only; can batch with another PR or defer
+- **Action:** If prioritized: create fresh `chore(config): pin black to version 23`, apply, test
+
+### General Guidelines for All Future PRs
+
+1. **Always create fresh branch from `upstream/master`:**
+   ```bash
+   git checkout upstream/master
+   git checkout -b feature-name
+   ```
+
+2. **Apply ONLY the changes for that specific concern:**
+   - No CI config unless directly required by feature
+   - No README updates unless directly required
+   - No format-only changes mixed with functional changes
+
+3. **Test before commit:**
+   ```bash
+   conda run -n dev python -m pytest tests/ -x -q
+   ```
+
+4. **Conventional commit format:**
+   ```
+   type(scope): subject line (50 chars max)
+   
+   - Bullet 1
+   - Bullet 2
+   - All X tests pass ✅
+   ```
+
+5. **Push to origin, create PR to bdaiinstitute:**
+   ```bash
+   git push origin branch-name
+   # Visit: https://github.com/bdaiinstitute/spatialmath-python/compare/master...petercorke:branch-name
+   ```
+
+---
+
+## Summary Table
+
+| PR | Branch | Commit | Status | Tests | Next Action |
+|---|---|---|---|---|---|
+| A | fix/export-base-functions | 40fad13 | ✅ Pushed | 19/19 | Create PR to RAI |
+| B | docs/sphinx-docstring-fixes | d4f56bf | ✅ Pushed | N/A (docs) | Monitor review |
+| C | fix/twist-pitch-clean | beef079 | ✅ Pushed | 25/25 | Create PR to RAI |
+| D | feat/imatmul | TBD | 🟡 Pending | ? | Create fresh branch, apply changes |
+| E | refactor/printline | TBD | 🟡 Pending | ? | Create fresh branch, apply changes |
+| F | feat/normalize-rotations | TBD | 🔴 Blocked | ? | Investigate completeness first |
+| G | chore(config):black | TBD | 🟡 Optional | N/A | Low priority, batch or defer |
+
+---
+
+## Key Contacts
+
+- **Jenny Barry** (jbarry-bdai): Main RAI reviewer
+- **Mark Yeatman** (myeatman-bdai): Secondary reviewer
+- **Repo:** bdaiinstitute/spatialmath-python
+
+---
+
+## Notes for Future Sessions
+
+1. **doco-fix branch:** Once PR-A and PR-B are merged, delete the old `doco-fix` branch (content is split)
+2. **norm-fix status:** Before working on PR-F, investigate whether `norm-fix` branch is feature-complete or blocked on design questions
+3. **PR reviews:** Check email/GitHub for feedback on PRs A, B, C—may require updates before merge
+4. **Version pinning:** All deprecations in this session use version 1.1.16; update if version bump happens
+
+---
+
+**Next Session Checklist:**
+- [ ] Create PR for PR-C (fix/twist-pitch-clean) to RAI
+- [ ] Monitor feedback on PR-A & PR-B
+- [ ] Investigate norm-fix branch completeness
+- [ ] Start PR-D (imatmul) or PR-E (printline) if A/B/C reviews are clear
+- [ ] Delete old branches (doco-fix, fix/twist-pitch) once cleaned up