delegation-propose-accept pattern in docs

docs-main/snippets/daml-docs/appdev_modules_m3-design-patterns_L530.mdx

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+```haskell
+choice Lock : ContractId LockedCoin
+  with maturity: Time; locker: Party
+  controller owner
+  do create LockedCoin with coin=this; maturity; locker
+```

docs-main/snippets/daml-docs/appdev_modules_m3-design-patterns_L533.mdx

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+```haskell
+template LockedCoin
+  with
+    coin: Coin
+    maturity: Time
+    locker: Party
+  where
+    signatory coin.issuer, coin.owner
+    observer locker
+
+    choice Unlock
+      : ContractId Coin
+      controller locker
+      do create coin
+```

docs-main/snippets/daml-docs/appdev_modules_m3-design-patterns_L535.mdx

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+```haskell
+-- a coin can only be archived by the issuer under the condition that the issuer is the owner of the coin. This ensures the issuer cannot archive coins at will.
+choice Archives
+  : ()
+  controller issuer
+  do assert (issuer == owner)
+```

docs-main/snippets/daml-docs/appdev_modules_m3-design-patterns_L536.mdx

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+```haskell
+template CoinCommitment
+  with
+    owner: Party
+    issuer: Party
+    amount: Decimal
+  where
+    signatory issuer
+    observer owner
+
+    nonconsuming choice LockCoin
+      : ContractId LockedCoin
+      with
+        coinCid: ContractId Coin
+        maturity: Time
+        locker: Party
+      controller owner
+      do
+        inputCoin <- fetch coinCid
+        assert (inputCoin.owner == owner && inputCoin.issuer == issuer && inputCoin.amount == amount)
+        -- the original coin is transferred to the issuer, then archived
+        prop <- exercise coinCid Transfer with newOwner = issuer
+        id <- exercise prop AcceptTransfer
+        exercise id Archives
+        create LockedCoin with
+          coin = inputCoin with owner; issuer; amount
+          maturity; locker
+```

docs-main/snippets/daml-docs/appdev_modules_m3-design-patterns_L555.mdx

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+```haskell
+template LockRequest
+  with
+    locker: Party
+    maturity: Time
+    coin: Coin
+  where
+    signatory locker
+    observer coin.owner
+
+    choice Accept : LockResult
+      with coinCid : ContractId Coin
+      controller coin.owner
+      do
+        inputCoin <- fetch coinCid
+        assert (inputCoin == coin)
+        tpCid <- exercise coinCid Transfer with newOwner = locker
+        coinCid <- exercise tpCid AcceptTransfer
+        lockCid <- create LockedCoinV2 with locker; maturity; coin
+        return LockResult {coinCid; lockCid}
+```

docs-main/snippets/daml-docs/appdev_modules_m3-design-patterns_L565.mdx

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+```haskell
+template LockedCoinV2
+  with
+    coin: Coin
+    maturity: Time
+    locker: Party
+  where
+    signatory locker, coin.owner
+
+    choice UnlockV2
+      : ContractId Coin
+      with coinCid : ContractId Coin
+      controller locker
+      do
+        inputCoin <- fetch coinCid
+        assert (inputCoin.owner == locker)
+        tpCid <- exercise coinCid Transfer with newOwner = coin.owner
+        exercise tpCid AcceptTransfer
+
+    choice ClawbackV2
+      : ContractId Coin
+      with coinCid : ContractId Coin
+      controller coin.owner
+      do
+        currTime <- getTime
+        assert (currTime >= maturity)
+        inputCoin <- fetch coinCid
+        assert (inputCoin == coin with owner=locker)
+        tpCid <- exercise coinCid Transfer with newOwner = coin.owner
+        exercise tpCid AcceptTransfer
+```