Add analytics tracking for component usage, user connections, and external links #407

User story / Problem statement

As a dApp developer using dAppBooster, I want an integrated analytics system so that I can track component usage frequency, monitor user connections, understand how users navigate the dApp, and see which external links they visit -- enabling data-driven decisions about feature development and UX improvements.

Expected outcome

When this is done, the dApp should capture and report on analytics data through PostHog (see #97), covering: component usage frequency, user connection counts, session replays for observing real user interactions, custom event tracking tailored to each dApp's needs, and external link navigation. All data should be accessible through a developer-facing dashboard for analysis.

Acceptance criteria

• Integrate PostHog (see Integrate PostHog #97) to log component usage frequency
• Generate reports showing most-used components and their usage counts
• Track the number of users connecting to the dApp
• Expose connection data in a developer-accessible dashboard
• Enable session replay so developers can observe how users interact with the dApp, catch bugs, and identify usability issues
• Support custom event tracking that developers can tailor to their specific use cases and user flows
• Track external link navigation from within the dApp
• Store and display external link data in analytics reports

Technical notes

• Depends on Integrate PostHog #97 (PostHog integration) being implemented first
• PostHog was chosen for its web analytics, session replay, and straightforward integration (see Integrate PostHog #97 for rationale)
• Custom events should cover the base universe of projects developers might build with dAppBooster
• Originally tracked in Add analytics to dappBooster.dev dAppBoosterLanding-v1#34