Add first-party verdict and guards to tracker mapping

The tracker-pattern catalog was binary (linked to a vendor or not), so
generic and first-party artifacts (loglevel keys, wallet-extension keys,
an org's own trackers) were retried forever and, once one row was wrongly
attributed, re-propagated to every organization with no re-check.

Give catalog rows a terminal attribution verdict (UNDETERMINED,
THIRD_PARTY, FIRST_PARTY): FIRST_PARTY short-circuits the whole mapping
pipeline so the artifact is never attributed again. Gate deterministic
vendor adoption behind a trust bar so only curated/operator rows
auto-propagate; lower-confidence agent/heuristic rows are reused as hints
and re-resolved, and an independent agent re-confirmation corroborates and
promotes them. Make the mapping agent emit an evidence source and reject
any attribution that lacks concrete evidence, and let it declare a
first-party verdict. Skip the speculative agent for PRE_EXISTING-source
patterns, whose low signal invites invented vendors.

Add proboctl "ctp mark-first-party" and an --attribution list filter to
audit and remediate existing wrong links, and a cursor rule documenting
migration naming so the timestamp is taken from date -u, not invented.

Signed-off-by: Émile Ré <emile@probo.com>

pkg/cookiebanner/prompts/tracker_identification.txt.tmpl

@@ -9,10 +9,12 @@ Return a structured JSON response with:
 - third_party_name: the canonical company/service name (e.g. "Google Analytics", not "google" or "GA")
 - category: the business category of the third party
 - third_party_confidence: how confident you are about WHICH company or service set this tracker (0.0 to 1.0). This is the confidence in the attribution alone — not a judgment of whether the artifact is a "real" web tracker. A browser-extension artifact whose name names its vendor can still warrant high confidence here.
+- evidence_source: the concrete evidence that backs the attribution — one of "database_match" (an exact pattern match in the internal database), "naming_convention" (the tracker's meaningful prefix or an embedded vendor name), "web_search" (a web result that names the setter), "browser_page" (a page you opened that names the setter), or "none" (no concrete evidence). It MUST be "none" whenever third_party_name is empty, and it MUST be a concrete kind (not "none") whenever you name a vendor — an attribution with evidence_source "none" is discarded.
+- is_first_party: true when the artifact has no third party at all — it is the scanned site's own tracker, a generic library or log key (e.g. "loglevel", "debug"), a browser-extension key that embeds the scanned site's origin, or otherwise not attributable to any external vendor. Leave it false whenever a vendor is or might be responsible.
 </task>
 
 <instructions>
-1. First use the search_tracker_patterns tool to look for similar known patterns in the database. Strip variable parts (IDs, UUIDs, timestamps) from the pattern name and search for the fixed prefix or root (e.g. for "_gat_UA-12345678-1", search for "_gat").
+1. First use the search_tracker_patterns tool to look for similar known patterns in the database. Strip variable parts (IDs, UUIDs, timestamps) from the pattern name and search for the fixed prefix or root (e.g. for "_gat_UA-12345678-1", search for "_gat"). Weigh the results by their confidence: a high-confidence match (a curated/seed entry) is authoritative, but a lower-confidence match is only a hint from an earlier automatic guess — corroborate it with the naming convention or a web/browser result before relying on it, and never treat it as proof on its own. Only count this as evidence_source "database_match" for an exact, high-confidence match on the same pattern.
 
 2. If search_tracker_patterns returns results with a third party name, use the search_third_parties tool to confirm the exact name in the database and get its category.
 
@@ -56,6 +58,10 @@ Return a structured JSON response with:
 
 10. Only attribute a tracker to a company or service when you have concrete evidence: an exact (perfect) match on the pattern in the database, an unmistakable naming convention where the tracker's meaningful prefix belongs to that vendor (including a vendor name embedded in the key), or a clear web search result whose tracker name shares that meaningful prefix. Absent a shared meaningful prefix or a perfect pattern match, do NOT imagine a vendor — never guess or invent attributions based on vague similarity, a shared generic word, or general knowledge. If no evidence supports a match, return an empty third_party_name with third_party_confidence below 0.3.
 
-11. For the category field, use one of: {{.Categories}}.
+11. Always set evidence_source to the kind of evidence you actually used for the attribution, and only to a concrete kind ("database_match", "naming_convention", "web_search", or "browser_page") when that evidence genuinely exists. If you are tempted to name a vendor from general knowledge or a vague resemblance with no concrete evidence, set evidence_source to "none" and leave third_party_name empty instead — an attribution carrying evidence_source "none" is rejected.
+
+12. Set is_first_party to true when the artifact plainly has no external vendor behind it. This covers: the scanned site's own trackers; generic developer/library keys that any application can write (e.g. "loglevel", "debug", "redux", framework-internal keys); a browser-extension key that embeds the scanned site's own origin (e.g. "ethereum-https://<scanned_site>"); and any key whose only plausible owner is the first party. A true value is a terminal verdict — the tracker will never be re-examined for a vendor — so only set it when you are confident no third party is responsible; when a vendor is or might be responsible, leave it false and attribute (or leave undetermined) instead.
+
+13. For the category field, use one of: {{.Categories}}.
    Most cookies fall under ANALYTICS or MARKETING.
 </instructions>