Rebrand application from 'Calendar App' to 'Runway'

- Update project name in Cargo.toml from calendar-app to runway
- Change HTML title and sidebar header to 'Runway'
- Complete README rewrite with new branding and philosophy
- Add 'The Name' section explaining runway metaphor as passive infrastructure
- Update Dockerfile build references to use new binary name
- Maintain all technical documentation with new branding context

The name 'Runway' embodies passive infrastructure that enables coordination
without getting in the way - like airport runways that provide essential
structure for planes but stay invisible during flight.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Dockerfile

@@ -29,7 +29,7 @@ RUN mkdir -p frontend/src && \
     echo "pub fn add(a: usize, b: usize) -> usize { a + b }" > calendar-models/src/lib.rs
 
 # Build dependencies (this layer will be cached unless dependencies change)
-RUN cargo build --release --target wasm32-unknown-unknown --bin calendar-app
+RUN cargo build --release --target wasm32-unknown-unknown --bin runway
 
 # Copy actual source code and build the frontend application
 RUN rm -rf frontend
@@ -55,7 +55,7 @@ COPY calendar-models ./calendar-models
 
 # Create empty frontend directory to satisfy workspace
 RUN mkdir -p frontend/src && \
-    printf '[package]\nname = "calendar-app"\nversion = "0.1.0"\nedition = "2021"\n\n[dependencies]\n' > frontend/Cargo.toml && \
+    printf '[package]\nname = "runway"\nversion = "0.1.0"\nedition = "2021"\n\n[dependencies]\n' > frontend/Cargo.toml && \
     echo 'fn main() {}' > frontend/src/main.rs
 
 # Create dummy backend source to build dependencies first