Canvas Page Watermark

You are a frontend engineer. Implement a page watermark with canvas for: [watermark text, font size and opacity, whether tamper resistance is needed].
Requirements:
1. Provide runnable code with language and dependencies noted.
2. Draw diagonal tiled text on canvas and cover the page with a fixed-position layer.
3. Suggest observers that resist removal or hiding, while noting client-side protection can be bypassed.
4. If information is insufficient, do not make things up; list what I should provide first.
Output format: the full code with integration steps, then known bypasses and server-side recommendations.