[feature] Push notifications (#3587)

* Update push subscription API model to be Mastodon 4.0 compatible

* Add webpush-go dependency

# Conflicts:
#	go.sum

* Single-row table for storing instance's VAPID key pair

* Generate VAPID key pair during startup

* Add VAPID public key to instance info API

* Return VAPID public key when registering an app

* Store Web Push subscriptions in DB

* Add Web Push sender (similar to email sender)

* Add no-op push senders to most processor tests

* Test Web Push notifications from workers

* Delete Web Push subscriptions when account is deleted

* Implement push subscription API

* Linter fixes

* Update Swagger

* Fix enum to int migration

* Fix GetVAPIDKeyPair

* Create web push subscriptions table with indexes

* Log Web Push server error messages

* Send instance URL as Web Push JWT subject

* Accept any 2xx code as a success

* Fix malformed VAPID sub claim

* Use packed notification flags

* Remove unused date columns

* Add notification type for update notifications

Not used yet

* Make GetVAPIDKeyPair idempotent

and remove PutVAPIDKeyPair

* Post-rebase fixes

* go mod tidy

* Special-case 400 errors other than 408/429

Most client errors should remove the subscription.

* Improve titles, trim body to reasonable length

* Disallow cleartext HTTP for Web Push servers

* Fix lint

* Remove redundant index on unique column

Also removes redundant unique and notnull tags on ID column since these are implied by pk

* Make realsender.go more readable

* Use Tobi's style for wrapping errors

* Restore treating all 5xx codes as temporary problems

* Always load target account settings

* Stub `policy` and `standard`

* webpush.Sender: take type converter as ctor param

* Move webpush.MockSender and noopSender into testrig

1 files changed, 276 insertions, 0 deletions

diff --git a/vendor/github.com/rivo/uniseg/sentencerules.go b/vendor/github.com/rivo/uniseg/sentencerules.go
new file mode 100644
index 000000000..0b29c7bdb
--- /dev/null
+++ b/vendor/github.com/rivo/uniseg/sentencerules.go
@@ -0,0 +1,276 @@
+package uniseg
+
+import "unicode/utf8"
+
+// The states of the sentence break parser.
+const (
+	sbAny = iota
+	sbCR
+	sbParaSep
+	sbATerm
+	sbUpper
+	sbLower
+	sbSB7
+	sbSB8Close
+	sbSB8Sp
+	sbSTerm
+	sbSB8aClose
+	sbSB8aSp
+)
+
+// sbTransitions implements the sentence break parser's state transitions. It's
+// anologous to [grTransitions], see comments there for details.
+//
+// Unicode version 15.0.0.
+func sbTransitions(state, prop int) (newState int, sentenceBreak bool, rule int) {
+	switch uint64(state) | uint64(prop)<<32 {
+	// SB3.
+	case sbAny | prCR<<32:
+		return sbCR, false, 9990
+	case sbCR | prLF<<32:
+		return sbParaSep, false, 30
+
+	// SB4.
+	case sbAny | prSep<<32:
+		return sbParaSep, false, 9990
+	case sbAny | prLF<<32:
+		return sbParaSep, false, 9990
+	case sbParaSep | prAny<<32:
+		return sbAny, true, 40
+	case sbCR | prAny<<32:
+		return sbAny, true, 40
+
+	// SB6.
+	case sbAny | prATerm<<32:
+		return sbATerm, false, 9990
+	case sbATerm | prNumeric<<32:
+		return sbAny, false, 60
+	case sbSB7 | prNumeric<<32:
+		return sbAny, false, 60 // Because ATerm also appears in SB7.
+
+	// SB7.
+	case sbAny | prUpper<<32:
+		return sbUpper, false, 9990
+	case sbAny | prLower<<32:
+		return sbLower, false, 9990
+	case sbUpper | prATerm<<32:
+		return sbSB7, false, 70
+	case sbLower | prATerm<<32:
+		return sbSB7, false, 70
+	case sbSB7 | prUpper<<32:
+		return sbUpper, false, 70
+
+	// SB8a.
+	case sbAny | prSTerm<<32:
+		return sbSTerm, false, 9990
+	case sbATerm | prSContinue<<32:
+		return sbAny, false, 81
+	case sbATerm | prATerm<<32:
+		return sbATerm, false, 81
+	case sbATerm | prSTerm<<32:
+		return sbSTerm, false, 81
+	case sbSB7 | prSContinue<<32:
+		return sbAny, false, 81
+	case sbSB7 | prATerm<<32:
+		return sbATerm, false, 81
+	case sbSB7 | prSTerm<<32:
+		return sbSTerm, false, 81
+	case sbSB8Close | prSContinue<<32:
+		return sbAny, false, 81
+	case sbSB8Close | prATerm<<32:
+		return sbATerm, false, 81
+	case sbSB8Close | prSTerm<<32:
+		return sbSTerm, false, 81
+	case sbSB8Sp | prSContinue<<32:
+		return sbAny, false, 81
+	case sbSB8Sp | prATerm<<32:
+		return sbATerm, false, 81
+	case sbSB8Sp | prSTerm<<32:
+		return sbSTerm, false, 81
+	case sbSTerm | prSContinue<<32:
+		return sbAny, false, 81
+	case sbSTerm | prATerm<<32:
+		return sbATerm, false, 81
+	case sbSTerm | prSTerm<<32:
+		return sbSTerm, false, 81
+	case sbSB8aClose | prSContinue<<32:
+		return sbAny, false, 81
+	case sbSB8aClose | prATerm<<32:
+		return sbATerm, false, 81
+	case sbSB8aClose | prSTerm<<32:
+		return sbSTerm, false, 81
+	case sbSB8aSp | prSContinue<<32:
+		return sbAny, false, 81
+	case sbSB8aSp | prATerm<<32:
+		return sbATerm, false, 81
+	case sbSB8aSp | prSTerm<<32:
+		return sbSTerm, false, 81
+
+	// SB9.
+	case sbATerm | prClose<<32:
+		return sbSB8Close, false, 90
+	case sbSB7 | prClose<<32:
+		return sbSB8Close, false, 90
+	case sbSB8Close | prClose<<32:
+		return sbSB8Close, false, 90
+	case sbATerm | prSp<<32:
+		return sbSB8Sp, false, 90
+	case sbSB7 | prSp<<32:
+		return sbSB8Sp, false, 90
+	case sbSB8Close | prSp<<32:
+		return sbSB8Sp, false, 90
+	case sbSTerm | prClose<<32:
+		return sbSB8aClose, false, 90
+	case sbSB8aClose | prClose<<32:
+		return sbSB8aClose, false, 90
+	case sbSTerm | prSp<<32:
+		return sbSB8aSp, false, 90
+	case sbSB8aClose | prSp<<32:
+		return sbSB8aSp, false, 90
+	case sbATerm | prSep<<32:
+		return sbParaSep, false, 90
+	case sbATerm | prCR<<32:
+		return sbParaSep, false, 90
+	case sbATerm | prLF<<32:
+		return sbParaSep, false, 90
+	case sbSB7 | prSep<<32:
+		return sbParaSep, false, 90
+	case sbSB7 | prCR<<32:
+		return sbParaSep, false, 90
+	case sbSB7 | prLF<<32:
+		return sbParaSep, false, 90
+	case sbSB8Close | prSep<<32:
+		return sbParaSep, false, 90
+	case sbSB8Close | prCR<<32:
+		return sbParaSep, false, 90
+	case sbSB8Close | prLF<<32:
+		return sbParaSep, false, 90
+	case sbSTerm | prSep<<32:
+		return sbParaSep, false, 90
+	case sbSTerm | prCR<<32:
+		return sbParaSep, false, 90
+	case sbSTerm | prLF<<32:
+		return sbParaSep, false, 90
+	case sbSB8aClose | prSep<<32:
+		return sbParaSep, false, 90
+	case sbSB8aClose | prCR<<32:
+		return sbParaSep, false, 90
+	case sbSB8aClose | prLF<<32:
+		return sbParaSep, false, 90
+
+	// SB10.
+	case sbSB8Sp | prSp<<32:
+		return sbSB8Sp, false, 100
+	case sbSB8aSp | prSp<<32:
+		return sbSB8aSp, false, 100
+	case sbSB8Sp | prSep<<32:
+		return sbParaSep, false, 100
+	case sbSB8Sp | prCR<<32:
+		return sbParaSep, false, 100
+	case sbSB8Sp | prLF<<32:
+		return sbParaSep, false, 100
+
+	// SB11.
+	case sbATerm | prAny<<32:
+		return sbAny, true, 110
+	case sbSB7 | prAny<<32:
+		return sbAny, true, 110
+	case sbSB8Close | prAny<<32:
+		return sbAny, true, 110
+	case sbSB8Sp | prAny<<32:
+		return sbAny, true, 110
+	case sbSTerm | prAny<<32:
+		return sbAny, true, 110
+	case sbSB8aClose | prAny<<32:
+		return sbAny, true, 110
+	case sbSB8aSp | prAny<<32:
+		return sbAny, true, 110
+	// We'll always break after ParaSep due to SB4.
+
+	default:
+		return -1, false, -1
+	}
+}
+
+// transitionSentenceBreakState determines the new state of the sentence break
+// parser given the current state and the next code point. It also returns
+// whether a sentence boundary was detected. If more than one code point is
+// needed to determine the new state, the byte slice or the string starting
+// after rune "r" can be used (whichever is not nil or empty) for further
+// lookups.
+func transitionSentenceBreakState(state int, r rune, b []byte, str string) (newState int, sentenceBreak bool) {
+	// Determine the property of the next character.
+	nextProperty := property(sentenceBreakCodePoints, r)
+
+	// SB5 (Replacing Ignore Rules).
+	if nextProperty == prExtend || nextProperty == prFormat {
+		if state == sbParaSep || state == sbCR {
+			return sbAny, true // Make sure we don't apply SB5 to SB3 or SB4.
+		}
+		if state < 0 {
+			return sbAny, true // SB1.
+		}
+		return state, false
+	}
+
+	// Find the applicable transition in the table.
+	var rule int
+	newState, sentenceBreak, rule = sbTransitions(state, nextProperty)
+	if newState < 0 {
+		// No specific transition found. Try the less specific ones.
+		anyPropState, anyPropProp, anyPropRule := sbTransitions(state, prAny)
+		anyStateState, anyStateProp, anyStateRule := sbTransitions(sbAny, nextProperty)
+		if anyPropState >= 0 && anyStateState >= 0 {
+			// Both apply. We'll use a mix (see comments for grTransitions).
+			newState, sentenceBreak, rule = anyStateState, anyStateProp, anyStateRule
+			if anyPropRule < anyStateRule {
+				sentenceBreak, rule = anyPropProp, anyPropRule
+			}
+		} else if anyPropState >= 0 {
+			// We only have a specific state.
+			newState, sentenceBreak, rule = anyPropState, anyPropProp, anyPropRule
+			// This branch will probably never be reached because okAnyState will
+			// always be true given the current transition map. But we keep it here
+			// for future modifications to the transition map where this may not be
+			// true anymore.
+		} else if anyStateState >= 0 {
+			// We only have a specific property.
+			newState, sentenceBreak, rule = anyStateState, anyStateProp, anyStateRule
+		} else {
+			// No known transition. SB999: Any × Any.
+			newState, sentenceBreak, rule = sbAny, false, 9990
+		}
+	}
+
+	// SB8.
+	if rule > 80 && (state == sbATerm || state == sbSB8Close || state == sbSB8Sp || state == sbSB7) {
+		// Check the right side of the rule.
+		var length int
+		for nextProperty != prOLetter &&
+			nextProperty != prUpper &&
+			nextProperty != prLower &&
+			nextProperty != prSep &&
+			nextProperty != prCR &&
+			nextProperty != prLF &&
+			nextProperty != prATerm &&
+			nextProperty != prSTerm {
+			// Move on to the next rune.
+			if b != nil { // Byte slice version.
+				r, length = utf8.DecodeRune(b)
+				b = b[length:]
+			} else { // String version.
+				r, length = utf8.DecodeRuneInString(str)
+				str = str[length:]
+			}
+			if r == utf8.RuneError {
+				break
+			}
+			nextProperty = property(sentenceBreakCodePoints, r)
+		}
+		if nextProperty == prLower {
+			return sbLower, false
+		}
+	}
+
+	return
+}