Fix: Change defparameter to defvar to prevent configuration reset on reload

[tamurashingo]

Summary

Fixed an issue where configuration values defined with defparameter were reset to their initial values when <app> was reloaded during clails test comm
and execution.

Problem

When executing the clails test command, the following problem occurred:

1. clails.boot loads <app> and initializes database configuration
2. During test execution, <app> is reloaded because <app-test> depends on <app>
3. Variables defined with defparameter are overwritten with initial values
4. Database configuration is lost or becomes incomplete

The following variables were particularly affected:

• clails/environment:*database-config*
• clails/environment:*database-type*
• Other application configuration variables

Changes

1. src/environment.lisp

Changed variables that application developers are expected to override from defparameter to defvar:

• *project-name*
• *project-dir*
• *project-environment*
• *database-config*
• *database-type*
• *migration-base-dir*
• *task-base-dir*
• *connection-pool*
• *routing-tables*
• *startup-hooks*
• *shutdown-hooks*
• *default-lock-mode*
• *sqlite3-busy-timeout*
• *sqlite3-lock-retry-count*
• *sqlite3-transaction-mode*
• *sqlite3-lock-module-loaded*
• *table-information-initialized*
• *query-initialization-callbacks*

2. src/middleware/transaction-middleware.lisp

• Changed *enable-transaction-middleware* to defvar

3. src/middleware/core.lisp

• Changed *clails-middleware-stack* to defvar

Rationale

defvar preserves existing values on re-evaluation, which is the standard Common Lisp behavior. This ensures:

• Configuration values are preserved even when files are reloaded
• Values set by application developers are not unintentionally reset
• Correct configuration is maintained during test execution

Testing

• Confirmed all existing tests pass
• Verified database configuration is correctly preserved during clails test command execution

Related Issue

Fixes #137