docs: overhaul documentation + add deployment guides

- ARCHITECTURE.md: update for v0.9.0/v0.9.3 — collections schema,
  collection_bills schema, alert_filters in notification_prefs,
  action_category in notification payload, migrations 0015/0016,
  /api/collections + /api/share endpoints, updated pages table,
  pipeline flow reflects categorize_action(), v0.9.0 and v0.9.3
  feature history entries
- ROADMAP.md: new file merging "MVP threshold" and "Feature Roadmap"
  docs into one clean shipped/upcoming/backlog structure with v1.0
  definition; removes stale design notes and duplicate entries
- DEPLOYING.md: new — prerequisites, .env setup, first run, admin
  account, domain/SSL with Caddy, useful commands
- UPDATING.md: new — SSH setup, manual deploy, deploy script, Gitea
  webhook + webhook listener, rollback procedure, env-only updates
- Delete: "MVP threshold this make v1 complete.md" and
  "PocketVeto — Feature Roadmap.md" (superseded by ROADMAP.md)
- how-it-works/page.tsx: accurate per-mode default alert sets,
  Alert Filters callout linking to Notifications settings
- notifications/page.tsx: Follow mode default includes amendment filed;
  Pocket Veto default excludes calendar placement

Authored-By: Jack Levy

frontend/app/how-it-works/page.tsx

@@ -5,6 +5,7 @@ import {
   Calendar,
   Clock,
   FileText,
+  Filter,
   Heart,
   HelpCircle,
   Rss,
@@ -82,29 +83,46 @@ export default function HowItWorksPage() {
       {/* Following */}
       <Section id="follow" title="Following bills" icon={Heart}>
         <p className="text-sm text-muted-foreground">
-          Follow any bill to track it. PocketVeto checks for changes — new text, amendments, status
-          updates — and notifies you through your configured channels. Three modes let you tune the
-          signal to your interest level.
+          Follow any bill to track it. PocketVeto checks for changes and notifies you through your
+          configured channels. Three modes let you tune the signal to your interest level — each
+          with its own independent set of alert filters.
         </p>
         <div className="space-y-3">
-          <Item icon={Heart} color="bg-red-100 text-red-600 dark:bg-red-900/30 dark:text-red-400" title="Following (neutral)">
-            Alerts on all material changes: new text published, amendments filed, and status updates
-            like floor votes or committee referrals.
+          <Item icon={Heart} color="bg-red-100 text-red-600 dark:bg-red-900/30 dark:text-red-400" title="Follow">
+            The standard mode. Default alerts: new bill text, amendments filed, chamber votes,
+            presidential action, and committee reports.
           </Item>
           <Item icon={Shield} color="bg-amber-100 text-amber-700 dark:bg-amber-900/30 dark:text-amber-400" title="Pocket Veto">
-            Alerts only when the bill advances toward becoming law — new official text, floor
-            scheduling, or committee passage. Useful when you oppose a bill and only need to act
-            if it gains traction.
+            For bills you oppose and only want to hear about if they gain real traction. Default
+            alerts: chamber votes and presidential action only — no noise from early committee or
+            document activity.
           </Item>
           <Item icon={Zap} color="bg-green-100 text-green-700 dark:bg-green-900/30 dark:text-green-400" title="Pocket Boost">
-            All the alerts of neutral mode, plus periodic reminders to contact your representative.
-            Use this when you actively support a bill and want to stay engaged.
+            For bills you actively support. Default alerts: everything — new text, amendments,
+            votes, presidential action, committee reports, calendar placement, procedural moves,
+            and committee referrals. Also adds &ldquo;Find Your Rep&rdquo; action buttons to push
+            notifications.
           </Item>
         </div>
+
+        <div className="rounded-md bg-muted/60 px-4 py-3 space-y-1.5">
+          <p className="text-xs font-medium flex items-center gap-1.5">
+            <Filter className="w-3.5 h-3.5" /> Adjusting alert filters
+          </p>
+          <p className="text-xs text-muted-foreground leading-relaxed">
+            The defaults above are starting points. In{" "}
+            <Link href="/notifications" className="text-primary hover:underline">Notifications → Alert Filters</Link>,
+            each mode has its own tab with eight independently toggleable alert types. For example,
+            a Follow bill where you don&apos;t care about committee reports — uncheck it and only
+            that mode is affected. Hit <strong>Load defaults</strong> on any tab to revert to the
+            preset above.
+          </p>
+        </div>
+
         <p className="text-xs text-muted-foreground">
-          You can also follow <strong>members</strong> (get alerts when they sponsor new bills) and{" "}
-          <strong>topics</strong> (get alerts when new bills matching that topic are briefed).
-          Member and topic follows use the neutral mode only.
+          You can also follow <strong>members</strong> (alerts when they sponsor new bills) and{" "}
+          <strong>topics</strong> (alerts when new bills matching that topic are briefed).
+          Member and topic follows use the Follow mode filters.
         </p>
       </Section>