Public listing pages accept invalid page values

[Jorel97]

Several server-rendered public listing pages parse searchParams.page directly with parseInt before deriving Supabase .range() offsets.

Affected pages include:

• /gigs
• /for-hire
• /directory
• /mcp
• /skills
• /prompts
• /affiliates

Repro

/gigs?page=-1
/prompts?page=abc
/affiliates?page=999999999

Observed from the page code:

• negative page values can produce negative Supabase ranges,
• non-numeric values can produce NaN ranges,
• huge values can produce runaway offsets.

Expected

Normalize page query values through a shared bounded parser before computing offsets, matching the recent API/query-helper pagination hardening.