docs: 补充第三方声明（MIT 合规）

- GridGeometry.kt 头部注明移植自 OrbitDeckiOS（Paul Stoetzer, N8HM, MIT）
- 新增 THIRD_PARTY_NOTICES.md：OrbitDeckiOS (MIT) + Material Design Icons (Apache-2.0)

THIRD_PARTY_NOTICES.md

@@ -0,0 +1,46 @@
+# Third-Party Notices
+
+Look4Sat-BA7OPF (this fork) bundles or adapts the following third-party
+components:
+
+## OrbitDeckiOS
+
+- Source: https://github.com/prstoetzer/OrbitDeckiOS
+- Copyright (c) 2025 Paul Stoetzer, N8HM
+- License: MIT
+- Used for: the Grid Finder feature — the VUCC grid line / grid point
+  geometry in `core/domain/.../utility/GridGeometry.kt` is ported from
+  OrbitDeckiOS' GridGeometry.
+
+### MIT License
+
+```
+MIT License
+
+Copyright (c) 2025 Paul Stoetzer, N8HM
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+```
+
+## Material Design Icons
+
+- Source: https://materialdesignicons.com (Pictogrammers)
+- License: Apache-2.0
+- Used for: `core/presentation/src/main/res/drawable/ic_grid_finder.xml`
+  (crosshairs-gps icon). Attribution is also noted in the icon file header.

core/domain/src/main/java/com/rtbishop/look4sat/core/domain/utility/GridGeometry.kt

@@ -14,6 +14,10 @@
  *
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ * Contains code ported from OrbitDeckiOS (https://github.com/prstoetzer/OrbitDeckiOS),
+ * Copyright (c) 2025 Paul Stoetzer, N8HM, licensed under the MIT License.
+ * See THIRD_PARTY_NOTICES.md for the full MIT license text.
  */
 package com.rtbishop.look4sat.core.domain.utility