Add ts config migrate for settings written for main

CHANGELOG.md

@@ -130,6 +130,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- `ts config migrate --adapter <adapter> <file>` rewrites a settings document written for an earlier release, such as one written before the breaking changes above, into the shape this release reads, and prints the result. The host's location lookup the earlier release ran becomes `[geo] module = "platform"` on Fastly and Cloudflare and no geo module on Axum and Spin, which have no lookup. On stderr it lists each change it made, each setting it left for the operator because it needs a decision or a value the document does not hold, such as `[geo] assume_single_jurisdiction` for an Edge Cookie module with no geo module, and each change in behavior no setting expresses, then checks the result with the settings validation `ts config validate` runs. It keeps the comments and the order of the tables, comments out a module that was not enabled under its new name, never selects `headers.geo`, which writes the reader's location, never prints a value from the document, rewrites the file in place with `--write`, and with `--check` changes nothing and exits 1 when the document needs migrating. Migrating a migrated document changes nothing.
 - A 51Degrees client hints middleware, `51degrees.client_hints`, from `crates/middleware/51degrees`, run by `[shared.51degrees]` and placed by a `[[serve]]` entry. On the Fastly adapter, the only one that runs request filters, it asks the 51Degrees service which client hints the reader's browser can send for each page navigation an entry covers, sending the `User-Agent` and `Sec-CH-UA` hints alone, and leaves the hint names in the request's state for the other 51Degrees modules, which keeps a page it names hints for out of the stored templates and sends it `private, no-store`. On each page an entry covers it writes `Accept-CH` and `Critical-CH` on the response unless the browser already sends every one of those hints, `Permissions-Policy` and the `Delegate-CH` tag that delegate those hints to the service's origin, each keeping every line the response already carries. `critical` in `[middleware.51degrees.client_hints]` turns the retry of the first navigation off. The service's answers load through the cache `51degrees-answers`, selected and sized in `[cache.51degrees-answers]`, and are held only where the build links a loading cache module, so a stock build asks the service for each page navigation an entry covers. What the 51Degrees modules share, being the table, the one call to the service, the evidence it sends and the cache its answer is held in, is the new `crates/shared/51degrees`.
 - `[middleware.<name>]`, a middleware's own settings table, written with the middleware's full name and read through `Settings::middleware_config`. A table holds values and arrays, a table within one is the longer name's table and never a setting, and a table at a name no running module supplies is refused at startup with the names that could be written.
 - A serve middleware may set headers on a response the publisher path sends for a request path its entry covers, through `Middleware::response_headers`, which is given the response's status and headers and runs whatever the response's media type and whether or not it has a body, so a redirect with no body reaches a middleware that rewrites its `Location`. A header it sets replaces one of the same name. The method is not called for a refusal made before the origin is asked, such as the `405` for a method a signed origin does not take, for a page served from the template cache or the refusal of such a page, or for an answer made from an error.

crates/trusted-server-cli/src/commands/audit/generate/mod.rs

@@ -7,7 +7,7 @@ mod gpt_slots;
 mod page_patterns;
 mod slot_toml;
 mod unit_template;
-mod validate;
+pub(crate) mod validate;
 
 use std::collections::BTreeSet;
 use std::fs;

crates/trusted-server-cli/src/commands/audit/generate/validate.rs

@@ -52,7 +52,7 @@ pub(super) fn check_candidate(candidate: &str, baseline: &str) -> CliResult<Vec<
 /// Parse and schema errors report only a byte offset. Deploy validation errors
 /// report only the failed phase because their messages can contain literal
 /// values, including validator parameters and invalid patterns.
-fn validate_source_config(source: &str) -> CliResult<()> {
+pub(crate) fn validate_source_config(source: &str) -> CliResult<()> {
     crate::app_config::register_linked_modules();
     let config: TrustedServerAppConfig = toml::from_str(source).map_err(|error| {
         error.span().map_or_else(