tracker-id and tracked-user-id processors

[amitu]

For incoming request does not have a tracker cookie, we should set a tracker cookie. This is used for analytics.

Earlier this discussion was so fastn creates the tracker id cookie, but based on cookie consent consideration its best we only create it after user opts in, and in which case wasm can handle tid creation.

tracker-id processor

We should also have a processor to get tracker id.

;; we do not need this in this query 
-- string tid:
$processor$: pr.tracker-id 

tracked-user-id processor

-- integer uid:
;; this processor looks for user via tracker id, this is only good for email
;; subscription scenarios
$processor$: pr.tracked-user-id 

[amitu]

FASTN_USE_TRACKER env should be set to false if you want to opt out of this feature.

[amitu]

fastn_tracker (table, will create). This will not have data. This will have nullable fk to fastn_user.

[amitu]

This should be based on cookie consent. We should not create the cookie till user has opted in, and in this case, the opt in action should create the tracker cookie, and the action can be part of subscription wasm. The reason to consider this feature as part of fastn was if we wanted to add tracker cookie on any page view (every page handler sees if tid cookie is set, if not creates tracker and sets this cookie), every page view action is more effecient if done directly in fastn, instead of via wasm.