docs: add v0.2.1 changelog entry (legible missing-template-field error)

the README changelog jumped from v0.2.0 to nothing; added the v0.2.1 entry documenting the legible ValueError for a template placeholder not supplied to next(**fields).

Signed-off-by: disqualifier <dev@disqualifier.me>

README.md

@@ -9,9 +9,9 @@ edits. **Credentials are always injected — never hardcoded.**
 ## Install
 
 ```
-aioproxies @ git+ssh://git@git.rethinkstudios.io/rethink-public/aioproxies.git@v0.2.0
+aioproxies @ git+ssh://git@git.rethinkstudios.io/rethink-public/aioproxies.git@v0.2.1
 # network helpers (current_ip / reset) need the extra:
-aioproxies[net] @ git+ssh://git@git.rethinkstudios.io/rethink-public/aioproxies.git@v0.2.0
+aioproxies[net] @ git+ssh://git@git.rethinkstudios.io/rethink-public/aioproxies.git@v0.2.1
 ```
 
 The core has no dependencies. The `net` extra adds `aiohttp` for `current_ip` /
@@ -200,6 +200,12 @@ await reset("https://provider/reset-url")    # rotate upstream ip
 
 ## Changelog
 
+### v0.2.1
+
+- **Legible missing-template-field error:** a `template=` placeholder not supplied to
+  `next(**fields)` now raises a clear `ValueError` naming the field, instead of leaking
+  a bare `KeyError` from `str.format`.
+
 ### v0.2.0
 
 - **Proxy health for rotating lists:** `burn`/`restore`/`is_burned` (dead `-1` vs

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "aioproxies"
-version = "0.2.0"
+version = "0.2.1"
 description = "proxy parsing, formatting, health, and pool management for aiohttp/aioweb, camoufox, and socks5"
 requires-python = ">=3.10"
 dependencies = []

src/aioproxies/__init__.py

@@ -18,4 +18,4 @@ __all__ = [
     "to_proxy",
 ]
 
-__version__ = "0.2.0"
+__version__ = "0.2.1"

src/aioproxies/manager.py

@@ -123,7 +123,13 @@ class AioProxies:
         if self._static is not None:
             return self._static
         if self.template is not None:
-            return parse(self.template.format(session=self.session_id(), **fields))
+            try:
+                filled = self.template.format(session=self.session_id(), **fields)
+            except (KeyError, IndexError) as exc:
+                raise ValueError(
+                    f"template placeholder {exc} not provided; pass it to next(**fields)"
+                ) from exc
+            return parse(filled)
         return self._next_from_list()
 
     def _next_from_list(self) -> Proxy: