fix: footprint param ignored, delete duplicates, add edit_schematic_component

Bug 1 - add_schematic_component: footprint parameter silently ignored
  The footprint value from MCP params was never passed through to
  DynamicSymbolLoader.add_component() / create_component_instance().
  Every placed symbol had an empty Footprint field regardless of input.
  Fix: added footprint: str='' to both functions, passed through all
  call sites, added footprint to schematic.ts tool schema.

Bug 2 - delete_schematic_component: only deleted first duplicate
  When a reference appeared multiple times (e.g. after a failed
  add attempt), only the first instance was removed due to break
  after first match. Fix: collect all matching blocks first, then
  delete back-to-front to preserve indices. Response now includes
  deleted_count.

New tool - edit_schematic_component
  Update footprint, value or reference of a placed symbol in-place.
  More efficient than delete+re-add: preserves position and UUID.
  Accepts: schematicPath, reference, footprint?, value?, newReference?

All 3 fixes verified by live tests on a real JLCPCB/KiCAD 9 project:
  - R_TEST1: footprint Resistor_SMD:R_0603_1608Metric written correctly
  - J1 duplicate: deleted_count=2 with single call
  - J2 edit: PinSocket footprint assigned in-place, no delete+add needed
  - PCB update (F8) confirmed: only components with footprint imported

CHANGELOG.md

@@ -4,44 +4,42 @@ All notable changes to the KiCAD MCP Server project are documented here.
 
 ## [2.2.1-alpha] - 2026-02-28
 
+### New MCP Tools
+
+- `edit_schematic_component` – Update properties of a placed symbol in-place (footprint,
+  value, reference rename). More efficient than delete + re-add: preserves position and UUID.
+
 ### Bug Fixes
 
+- `add_schematic_component`: `footprint` parameter was accepted but silently ignored – the
+  value was never passed through to `DynamicSymbolLoader.add_component()` /
+  `create_component_instance()`. All newly placed symbols always had an empty Footprint
+  field. Fix: added `footprint: str = ""` to both functions and threaded it through every
+  call site including the TypeScript tool schema.
+
+- `delete_schematic_component`: only deleted the first matching instance when duplicate
+  references existed (e.g. after an aborted add attempt). Root cause: loop used `break`
+  after the first match. Fix: collect all matching blocks first, then delete them all back-
+  to-front (to preserve line indices). Response now includes `deleted_count`.
+
 - `templates/*.kicad_sch`, `project.py`, `schematic.py`: Update KiCAD schematic format
-  version from `20230121` (KiCAD 7) to `20250114` (KiCAD 9).
+  version from `20230121` (KiCAD 7) to `20250114` (KiCAD 9). The MCP server targets
+  KiCAD 9 exclusively (`pcbnew.pyd` compiled for KiCAD 9.0, Python 3.11.5) – generating
+  files in an outdated format caused a spurious "This file was created with an older
+  KiCAD version" warning on every newly created schematic.
 
-  **Root cause:** The MCP server targets KiCAD 9 exclusively – `pcbnew.pyd` is compiled
-  for KiCAD 9.0 / Python 3.11.5, and the server explicitly selects the KiCAD 9 bundled
-  Python on Windows. Generating new schematics with a 2-year-old format tag caused a
-  spurious "This file was created with an older KiCAD version, it will be updated on
-  save" dialog on every newly created schematic, which confused users into thinking
-  something was broken.
+- `template_with_symbols_expanded.kicad_sch`: Remove 13 corrupt `_TEMPLATE_*` placed-symbol
+  blocks with `(lib_id -100)` – an integer caused by old sexpdata serializer (same bug
+  PR #40 fixed for the add path). KiCAD crashed with a null-pointer when selecting these
+  symbols. They appeared as grey `_TEMPLATE_R?`, `_TEMPLATE_U_REG?` etc. labels far
+  outside the sheet boundary (~5000mm off-sheet).
 
-  **Fix:** Updated header in all 4 template files and both inline schematic generators
-  (`project.py`, `schematic.py`) to emit `(version 20250114)`.
+  **Discovered via:** live testing on a real JLCPCB/KiCAD 9 project.
+  **Affected users:** schematics created from this template before this fix contain the
+  same corrupt blocks – remove all `(symbol (lib_id -100) ...)` blocks whose Reference
+  starts with `_TEMPLATE_`.
 
-- `template_with_symbols_expanded.kicad_sch`: Remove 13 corrupt `_TEMPLATE_*`
-  placed-symbol blocks containing `(lib_id -100)`.
-
-  **Root cause:** The expanded template was generated by the old sexpdata serializer
-  (the same corruption PR #40 fixed for the DynamicSymbolLoader add-path). The serializer
-  converted the string `"Device:R"` to the integer `-100`, producing `(lib_id -100)`
-  instead of `(lib_id "Device:R")`. KiCAD cannot resolve an integer as a library
-  reference and crashes with a null-pointer when the user attempts to select or box-select
-  these symbols. They appeared as grey `_TEMPLATE_R?`, `_TEMPLATE_C?`, `_TEMPLATE_U_REG?`
-  etc. labels ~5000 mm outside the sheet boundary – invisible during normal work but
-  triggering a crash when accidentally selected.
-
-  **Discovered via:** Live testing on a real JLCPCB/KiCAD 9 project where Claude Desktop
-  (via MCP) created a schematic from the expanded template.
-
-  **Fix:** Removed all 13 `_TEMPLATE_*` placed-symbol blocks using parenthesis-depth
-  tracking (same text-manipulation approach as PR #40). The `lib_symbols` section
-  (symbol definitions) is unchanged – only the corrupt placed instances were removed.
-
-  **Affected users:** Any schematic created from `template_with_symbols_expanded.kicad_sch`
-  before this fix contains the same corrupt blocks. To clean an existing schematic,
-  remove all `(symbol (lib_id -100) ...)` blocks whose `Reference` property starts
-  with `_TEMPLATE_`.
+---
 
 ---