Prepare connectrpc 0.3.2 release

[iainmcgin]

Lockstep bump of all three crates to 0.3.2: connectrpc, connectrpc-codegen, connectrpc-build.

Headline

#32 — generated service code no longer emits top-level use statements, so multiple service files can be include!d into the same Rust module without E0252 collisions. This was the proximate motivation for cutting 0.3.2 (it unblocks downstream consumers using buffa-packaging's flat output strategy).

Other changes shipping in 0.3.2

• fix: use service name const instead of string literal in generated clients #16 — generated client methods reference the per-service *_SERVICE_NAME const instead of repeating the fully-qualified service name as a string literal at every call site.
• Add wasm32 support and browser-based client example #19 — wasm32-unknown-unknown target compatibility for the connectrpc crate (default features off), plus a new examples/wasm-client demonstrating a Fetch-based ClientTransport. As a side effect of this PR, the workspace tokio feature footprint narrowed: published connectrpc previously inherited the full workspace tokio feature set when workspace = true was inlined at publish time, and now requests only rt, io-util, sync, time (plus net when the client/server feature is enabled). Downstream crates that use tokio directly should declare their own features rather than relying on transitive activation.
• Update outdated dependencies #37 — workspace dependency updates.

Notes

• Path-dep version constraint (build → codegen) already uses caret "0.3", so no change required there.
• README dependency snippets are caret "0.3", unchanged.
• CHANGELOG gains a 0.3.2 section with the four entries above.

[iainmcgin]

cc @windsornguyen once this is pushed to crates.io, let me know if it solves your issues or if there is more to do!