Split skill files to follow 500-line content guideline

[Copilot]

• Split igniteui-angular-components/SKILL.md (653 → 2 files ≤500 lines)
• Split igniteui-angular-grids/SKILL.md (1049 → 3 files ≤500 lines)
• Split igniteui-angular-grid-data-operations/SKILL.md (1691 → 4 files ≤500 lines)
• Keep igniteui-angular-theming/SKILL.md with added Related Skills section
• Add proper cross-references (Related Skills with links) to all 10 skill files
• Update .github/copilot-instructions.md and README.md with new skill listings
• Fix: Remote Paging example now sets [pagingMode]="pagingMode" (GridPagingMode.Remote) on the grid
• Fix: Complete Remote Data Pattern now uses (filteringExpressionsTreeChange) instead of (filteringDone)
• Added filteringExpressionsTreeChange to the Filtering Events table in grid-data-operations with a remote data note
• Trim duplicate editing/summaries content in grids-features (331 → 228 lines): replaced detailed Cell Editing, Row Editing, Batch Editing, Row Adding/Deleting, Validation, and Summaries sections with redirect pointers to grid-editing; quick-reference tables retained for at-a-glance use

---

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.

[zdrawku]

@copilot, here a few issues I noticed:

1. the remote paging template in the igniteui-angular-grid-paging-remote skill is missing pagingMode -

We should set Grid's pagingMode property to GridPagingMode.remote. Also it is necessary to either subscribe to pagingDone or perPageChange events in order to fetch the data from your remote service, it depends on the use case which event will be used.

Without it, the grid will attempt client-side pagination over whatever page-slice the server returns, producing incorrect results. The SKILL does mention this correctly in the "Remote Paging with custom igx-paginator-content" note block (GridPagingMode.Remote should be set), but the primary Remote Paging example simply omits it entirely.

2. Wrong event for remote filtering
   The SKILL's complete remote data pattern template uses:

The docs consistently use filteringExpressionsTreeChange for remote filtering:

"you need to subscribe to the dataPreLoad, sortingExpressionsChange and filteringExpressionsTreeChange outputs"

filteringDone is a column-level event (fires with IFilteringExpressionsTree for a single column). filteringExpressionsTreeChange is the grid-level output that reflects the whole filter state and is the correct one to debounce and forward to the server. Using filteringDone could cause missed updates (e.g., clearing all filters) or scope problems.

[Copilot]

@copilot, here a few issues I noticed:

1. the remote paging template in the igniteui-angular-grid-paging-remote skill is missing pagingMode -
   ...

Fixed in 69c6fd6:

1. Remote Paging — missing pagingMode: Added import { GridPagingMode } from 'igniteui-angular/grids/grid', set pagingMode = GridPagingMode.Remote on the component, and bound [pagingMode]="pagingMode" on the grid element. Without this, the grid would apply client-side pagination on top of the server's page slice.

2. Remote filtering event: Replaced (filteringDone)="onFilteringDone()" with (filteringExpressionsTreeChange)="onFilteringExpressionsTreeChange()" in the complete remote data pattern template, and updated the handler name and Key Points rule Style the list component #5 accordingly. Also added filteringExpressionsTreeChange to the Filtering Events table in the grid-data-operations skill with a note clarifying when each event should be used (filteringDone = column-scoped, filteringExpressionsTreeChange = grid-level for remote data).

[zdrawku]

@copilot there is a duplicate content
igniteui-angular-grids-features overlaps significantly with igniteui-angular-grid-editing — both cover cell editing, row editing, batch editing, row adding/deleting, and validation. The features skill is the older summary-style skill; the editing skill is the newer detailed one. They cross-link each other, which is correct, but the editing section content in grids-features could be trimmed to just redirect pointers to reduce token cost and prevent drift.

[Copilot]

@copilot there is a duplicate content
igniteui-angular-grids-features overlaps significantly with igniteui-angular-grid-editing — both cover cell editing, row editing, batch editi...

Fixed in 1c59500. Replaced the detailed Cell Editing, Row Editing, Batch Editing, Row Adding/Deleting, Validation, and Summaries sections in grids-features with redirect pointers to grid-editing, retaining only a quick-reference table for at-a-glance mode selection. The file dropped from 331 → 228 lines.