[FEATURE] Configurable slash command suggestion count in picker

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

Users who install multiple plugins and define custom skills accumulate 50+ slash commands. The picker displays a fixed number of suggestions with no way to configure the count. This makes discovery and selection slower than necessary, especially when commands share prefixes or similar names.

The recent improvements to character highlighting and description wrapping (v2.1.119) help readability, but the hard-coded suggestion limit still forces excessive scrolling or precise-query typing to find the right command.

Proposed Solution

Add a setting to control how many slash command suggestions the picker displays at once. Configurable via /config or settings.json:

{
  "slashCommandSuggestionCount": 15
}

The current count becomes the default. Users who need more visibility can increase it. The picker height adjusts accordingly.

Alternative Solutions

• Scrolling through the full list — works but slow with many entries
• Typing a more specific query — narrows results, but requires already knowing what you're looking for
• Using /skills or /help — shows all commands but breaks flow since you leave the input context

Priority

Medium - Would be very helpful

Feature Category

Configuration and settings

Use Case Example

1. I have 80+ slash commands from plugins, custom skills, and built-in commands
2. I type / and see a small fixed-size list
3. I want to find a skill I installed last week but don't remember the exact name
4. I scroll through the picker or guess at prefix queries, trying multiple times
5. With a configurable suggestion count (set to 20-25), I could scan more options at a glance and find the command faster without leaving the input context

Additional Context

This pairs well with the v2.1.119 improvements to the slash command picker (character match highlighting, multi-line description wrapping). Increasing the visible suggestion count would compound those gains for power users.