fix(bot-detection): respect trackOnlyCategories in generic isBot() fallback

Description

In detectBot(), when a User-Agent is not matched by literal/regex patterns in ua-patterns.ts or by isAIBot(), it falls back to isBot() from ua-parser-js.

Currently, this generic fallback branch hardcodes action: BotAction.BLOCK instead of routing through getAction(BotCategory.UNKNOWN_BOT, config):

if (isBot(userAgent)) {
    return {
        isBot: true,
        category: BotCategory.UNKNOWN_BOT,
        name,
        action: BotAction.BLOCK,   // ignores config.trackOnlyCategories
        confidence: 70,
        reason: "general_bot_pattern",
    };
}

As a result, configuring trackOnlyCategories: [BotCategory.UNKNOWN_BOT] does not apply to traffic detected via this fallback, and action: "block" is returned instead of "track_only".

Example:
A User-Agent like PowerShell/7.1.0 (which is recognized as a CLI tool by ua-parser-js's isBot() but is not present in ua-patterns.ts or isAIBot()):

detectBot("PowerShell/7.1.0", {
  trackOnlyCategories: [BotCategory.UNKNOWN_BOT],
});
Expected: action: "track_only"
Actual: action: "block"
Proposed Fix
Route the generic isBot() fallback through getAction():

action: getAction(BotCategory.UNKNOWN_BOT, config),

I have verified the fix and tests locally and can open a PR once this issue is accepted.

Start at detectBot() and the generic isBot() fallback, alongside ua-patterns.ts and isAIBot(), then compare its action handling with getAction(). Done means trackOnlyCategories applies to UNKNOWN_BOT detections, including the PowerShell example, with the expected track_only action; verify this with the relevant tests.